Been thinking of writing this for a while, and I decided today was going to be the time. However today our illustrious leader Gazebo decided to release a patch to change a few things. I'm mostly going to ignore that patch as I don't feel like testing it out before writing this. This text is going to suggest other solutions to the same problems that the patch have already solved however, so deal with it 
Keep in mind that this thread cares as much about the 'fun factor' as it does about balance, this is a side-effect of me only caring about fun and me thinking balance is fun.
TRADITION
Mostly everything about tradition feels nice and unique, powerful in its own way but still balanced. At first glance it seems mostly focused on the capital, but there are a lot of powerful effects that affects all of your cities. I'd be happy if all trees were as well designed and thought out as tradition, well done G.
Opener: 2 Culture in the capital.
As far as openers go, this is probably the most meh one in the game, it does what it is supposed to do, but isn't really fun for anyone. Sad considering how unique the rest of the tree feels like.
Scaling:+5% +3*X Growth in all cities.
Just really solid.
Finisher:+1 happiness for every national wonder
This finisher is sad and pathetic, really. Sure it provides you with a decent amount of happiness eventually, but most of the time I tend to forget it even exists. Definitely not fun.
Authority: +1 Culture in all cities. +2 hammers +3 Def +25 hp +engineer.
All around just good, I don't think I've ever picked Sovereignty over this one, which might be a problem, but I just don't care. It is awesome.
Sovereignty: +1 Gold +10% border expand in all cities. +2 gold +merchant.
Absolutely not bad by any means. It is going to provide a lot less gold than other policies but since the gold is added straight to the city it combats poverty. Border-expansion is solid, even if it feels like a really low number at this point.
Majesty: +20% GA duration, +10% culture +2 culture +writer +wslot.
Everything about this is solid really. I usually end up working way less cultural specialists than I did in vanilla for some reason, honestly don't know why, probably an error on my part.
Splendor: +2 Food in all cities. +1culture for monuments +2 culture for garden. +2 Food +Artist.
Probably the best policy in the tree, everything it gives is solid and most of it is global.
Devotion: +15% GPR in all cities. +2 faith +musician +mslot.
By far the least impressive of the tradition-buildings. The global bonus from the policy however makes up for that. The building would be far more impressive if it arrived early enough to help you secure a pantheon (or allow you to skip a shrine).
All in all, if I was to change something about Tradition it would be the opener/finisher or somehow move the faith from the court chapel earlier in the tree, maybe to the first tier, that might actually make the first tier a choice. Production or an early pantheon, probably not much of a choice.
LIBERTY
I've always liked Liberty, even back when it was useless, even back when it was boring, even back when it was overpowered. At this point liberty feels pretty good, balancewise but in my eyes it falls short when it comes to fun, most of that stems from two problems that I'll discuss below.
Opener: +10 culture when construct a building or research a tech.
A pretty fun opener, translates to about as much culture as the tradition opener, but it feels more fun and doesn't reduce unhappiness from boredom(ironic
). No idea if the culture gained affects border-growth, but it should and it probably does.
Scaling: +5% +2*X% production-bonus when building buildings.
The silent hero of the tree. Probably a lot more powerful than the tradition scaling bonus, but I only base that on gut-feelings
. Anyways I love it.
Finisher: A free great person of your choice.
I have always hated this finisher, always. It is probably better than the tradition finisher but honestly I don't care. One-shot policies are boring, one-shot finishers are even more boring. If something is one-shot, at least let it have some lingering effect like the Aesthetics free great person or free golden age.
Civil Engineers: +2 production in all cities -50% maintenance for roads.
Extra production helps your cities get started and cheaper roads makes it easier to connect your cities without running a gold deficit early on. All around solid.
City Planning: +30 gold from city-growth. +40 science from capital growth. Scales with era.
Pretty much the policy that makes liberty work. It gives you loads of gold and it gives you an early tech advantage that you can snowball. While I like the idea behind the tech I feel like it is way too powerful and available way too early in the tree. It just carries a way too big part of the liberty tree power.
Citizenship: Free worker +25% faster improvements.
The free worker is nice, it is a one-shot ability but it is more of a backup for the faster improvements. Improvements takes forever to finish, and this policy cuts that time down to forever*0.8 which is a significant difference. All around this policy makes building improvements less annoying, which is great.
Representation: +1 global happiness/15 citizens.
I feel like this policy might have been nerfed too much. If the happiness doesn't get bumped up it should probably get something else because this is going to provide you with 1 or maybe 2 happiness at most during the time where liberty is relevant.
Meritocracy: +1 movement for civilian units. +50 culture and GAP when you pop a GP. Scales with era.
All around solid, you don't really look forward to it as it doesn't feel like much of a change, but if you delay it in favor of getting 1 happiness from representation you're going to be a sad panda when you get a GP before you have enough culture to pick up Meritocracy. All around it feels rather boring, but it is solid.
I feel like Liberty might be in need of some major reconstruction. Most policies by themselves are pretty solid but I don't like how two of them just feels boring to grab while one pretty much provides you with half the power of the entire tree. I would shift some power around, lower the numbers for city-planning and move it or the meritocracy bonus to the finisher instead of the free GP. Add or move something minor to Representation and then add a new policy in place of what got moved to the finisher. No idea what the new policy would be however.
HONOR
I'm not as familiar with the Honor policy-tree as perhaps I should be. I've picked it up a few times and I've made it work, but I'm hardly an expert. It is not that I find the tree bad, or boring or anything like that I've just not rolled enough leaders that actually benefits from the honor bonuses and those that I've actually rolled have ended up gone other ways. In all the tree is pretty solid it does have some problems however.
Opener: +25% bonus when fighting barbs. Culture from killing barbs and grabbing barbcamps.
The active opener. The culture from this is really solid especially on large maps. You have to put some effort into it however, and it is a lot less useful and goes obsolete a lot faster on more crowded maps. The combat-bonus is awesome and makes those obscenely OP barb horsemen more manageable.
Scaling: +5% +4*X% production-bonus when building land-units.
The bonus is a lot bigger than the liberty one, probably because you tend to build more buildings than units. This does make a big difference however and building a large army is a lot easier with such a big bonus.
Finisher: Culture and GAP when capturing cities.
Pretty situational, you're forced into conquering cities to make any use of this. It does however make a pretty big difference and is all around a solid finisher, at least compared to the tradition and liberty ones. It is however rather sad that you're pretty much forced to delay your conquest until you're finished with the Honor tree or you'll miss out on these bonuses.
Logistics: +Science and +15 healing from kills.
All around solid, makes barb-hunting a lot easier and helps speed up your tech. Unlike the other trees the tier ones in Honor actually makes up a hard choice (at least for me, but it might be out of inexperience).
Tribute: +25% Border expansion. +10 gold and production from border-expansion. Scales with era.
Used to be a lot better. It is still really solid, would probably still be solid even if it just provided the % border expansion. Again this makes a hard choice.
Expansionism: Free settler. +1 happiness +1 culture from garrisons.
Speeds up your expansion, keeps your happiness and policy-rate solid. Helps border-expansions in new cities to help them produce faster, what's not to like? You're forced to keep garrisons in all cities, which you probably should anyways, costs some upkeep but that's a cheap price to pay.
Conscription: +10% CS for all units. Gain a ranged unit, and another one in each city settled after picking this policy.
All around awesome. You now get the garrison-unit needed for Expansionism for free. Not only that but you have a slight CS advantage over people without Conscription. The free units makes a slight overlap with the Scaling bonus, making less use out of the production-bonus because you get the units for free.
Martial Law: Extra production in puppets and occupied cities. -15% maintenance for units.
Always kinda weird to have the last policy in a tree feel like the weakest one. Martial Law isn't bad, really, it just promotes a weird play-style. The lowered maintenance is always solid, no doubt about it. The production in occupied cities is only ever useful for building the courthouse, but that's fine. The production-bonus in puppets is okay I guess even if puppets tend to construct buildings just fine on their own, and that's pretty much all they ever do. I guess the idea is to puppet a city, let it build its buildings and then annex it and have it build a courthouse when it no longer have any useful buildings left to build. That makes a pretty solid foundation for your cities before you decide to annex them. Only real problem is that puppet seems to not actually want to build most useful buildings at all for some reasons.
There isn't really that much I would change about Honor, the policies all fit pretty well together. I'm not a huge fan of the play style you're pretty much forced into when you play Honor, but on the other hand there isn't really any other way to handle the expansion/military tree other than that. It's not like I tend to play completely peaceful or anything like that, I just don't like the game telling me what to do I guess, I like it being my choice when I rain fire and death down on my neighbors for placing stupid cities too close to my borders.
All above:
I noticed a pretty boring trend with the ancient era trees, and that's that the Finisher is generally really meh, all medieval and Renaissance trees have really interesting finishers. I understand that the ancient era trees are supposed to be less powerful, but they can at least have two effects just like all other finishers have.
I was going to include all Policy-trees in this one from the start, but after writing just 3 of them I realized that this is going to be a huge project and that I should probably split them into different threads, and also different days because now my head hurts. Good night.
Also these are all just my opinions, feel free to discuss and disagree and whatever you want.

Keep in mind that this thread cares as much about the 'fun factor' as it does about balance, this is a side-effect of me only caring about fun and me thinking balance is fun.
TRADITION
Mostly everything about tradition feels nice and unique, powerful in its own way but still balanced. At first glance it seems mostly focused on the capital, but there are a lot of powerful effects that affects all of your cities. I'd be happy if all trees were as well designed and thought out as tradition, well done G.
Opener: 2 Culture in the capital.
As far as openers go, this is probably the most meh one in the game, it does what it is supposed to do, but isn't really fun for anyone. Sad considering how unique the rest of the tree feels like.
Scaling:+5% +3*X Growth in all cities.
Just really solid.
Finisher:+1 happiness for every national wonder
This finisher is sad and pathetic, really. Sure it provides you with a decent amount of happiness eventually, but most of the time I tend to forget it even exists. Definitely not fun.
Authority: +1 Culture in all cities. +2 hammers +3 Def +25 hp +engineer.
All around just good, I don't think I've ever picked Sovereignty over this one, which might be a problem, but I just don't care. It is awesome.
Sovereignty: +1 Gold +10% border expand in all cities. +2 gold +merchant.
Absolutely not bad by any means. It is going to provide a lot less gold than other policies but since the gold is added straight to the city it combats poverty. Border-expansion is solid, even if it feels like a really low number at this point.
Majesty: +20% GA duration, +10% culture +2 culture +writer +wslot.
Everything about this is solid really. I usually end up working way less cultural specialists than I did in vanilla for some reason, honestly don't know why, probably an error on my part.
Splendor: +2 Food in all cities. +1culture for monuments +2 culture for garden. +2 Food +Artist.
Probably the best policy in the tree, everything it gives is solid and most of it is global.
Devotion: +15% GPR in all cities. +2 faith +musician +mslot.
By far the least impressive of the tradition-buildings. The global bonus from the policy however makes up for that. The building would be far more impressive if it arrived early enough to help you secure a pantheon (or allow you to skip a shrine).
All in all, if I was to change something about Tradition it would be the opener/finisher or somehow move the faith from the court chapel earlier in the tree, maybe to the first tier, that might actually make the first tier a choice. Production or an early pantheon, probably not much of a choice.
LIBERTY
I've always liked Liberty, even back when it was useless, even back when it was boring, even back when it was overpowered. At this point liberty feels pretty good, balancewise but in my eyes it falls short when it comes to fun, most of that stems from two problems that I'll discuss below.
Opener: +10 culture when construct a building or research a tech.
A pretty fun opener, translates to about as much culture as the tradition opener, but it feels more fun and doesn't reduce unhappiness from boredom(ironic

Scaling: +5% +2*X% production-bonus when building buildings.
The silent hero of the tree. Probably a lot more powerful than the tradition scaling bonus, but I only base that on gut-feelings

Finisher: A free great person of your choice.
I have always hated this finisher, always. It is probably better than the tradition finisher but honestly I don't care. One-shot policies are boring, one-shot finishers are even more boring. If something is one-shot, at least let it have some lingering effect like the Aesthetics free great person or free golden age.
Civil Engineers: +2 production in all cities -50% maintenance for roads.
Extra production helps your cities get started and cheaper roads makes it easier to connect your cities without running a gold deficit early on. All around solid.
City Planning: +30 gold from city-growth. +40 science from capital growth. Scales with era.
Pretty much the policy that makes liberty work. It gives you loads of gold and it gives you an early tech advantage that you can snowball. While I like the idea behind the tech I feel like it is way too powerful and available way too early in the tree. It just carries a way too big part of the liberty tree power.
Citizenship: Free worker +25% faster improvements.
The free worker is nice, it is a one-shot ability but it is more of a backup for the faster improvements. Improvements takes forever to finish, and this policy cuts that time down to forever*0.8 which is a significant difference. All around this policy makes building improvements less annoying, which is great.
Representation: +1 global happiness/15 citizens.
I feel like this policy might have been nerfed too much. If the happiness doesn't get bumped up it should probably get something else because this is going to provide you with 1 or maybe 2 happiness at most during the time where liberty is relevant.
Meritocracy: +1 movement for civilian units. +50 culture and GAP when you pop a GP. Scales with era.
All around solid, you don't really look forward to it as it doesn't feel like much of a change, but if you delay it in favor of getting 1 happiness from representation you're going to be a sad panda when you get a GP before you have enough culture to pick up Meritocracy. All around it feels rather boring, but it is solid.
I feel like Liberty might be in need of some major reconstruction. Most policies by themselves are pretty solid but I don't like how two of them just feels boring to grab while one pretty much provides you with half the power of the entire tree. I would shift some power around, lower the numbers for city-planning and move it or the meritocracy bonus to the finisher instead of the free GP. Add or move something minor to Representation and then add a new policy in place of what got moved to the finisher. No idea what the new policy would be however.
HONOR
I'm not as familiar with the Honor policy-tree as perhaps I should be. I've picked it up a few times and I've made it work, but I'm hardly an expert. It is not that I find the tree bad, or boring or anything like that I've just not rolled enough leaders that actually benefits from the honor bonuses and those that I've actually rolled have ended up gone other ways. In all the tree is pretty solid it does have some problems however.
Opener: +25% bonus when fighting barbs. Culture from killing barbs and grabbing barbcamps.
The active opener. The culture from this is really solid especially on large maps. You have to put some effort into it however, and it is a lot less useful and goes obsolete a lot faster on more crowded maps. The combat-bonus is awesome and makes those obscenely OP barb horsemen more manageable.
Scaling: +5% +4*X% production-bonus when building land-units.
The bonus is a lot bigger than the liberty one, probably because you tend to build more buildings than units. This does make a big difference however and building a large army is a lot easier with such a big bonus.
Finisher: Culture and GAP when capturing cities.
Pretty situational, you're forced into conquering cities to make any use of this. It does however make a pretty big difference and is all around a solid finisher, at least compared to the tradition and liberty ones. It is however rather sad that you're pretty much forced to delay your conquest until you're finished with the Honor tree or you'll miss out on these bonuses.
Logistics: +Science and +15 healing from kills.
All around solid, makes barb-hunting a lot easier and helps speed up your tech. Unlike the other trees the tier ones in Honor actually makes up a hard choice (at least for me, but it might be out of inexperience).
Tribute: +25% Border expansion. +10 gold and production from border-expansion. Scales with era.
Used to be a lot better. It is still really solid, would probably still be solid even if it just provided the % border expansion. Again this makes a hard choice.
Expansionism: Free settler. +1 happiness +1 culture from garrisons.
Speeds up your expansion, keeps your happiness and policy-rate solid. Helps border-expansions in new cities to help them produce faster, what's not to like? You're forced to keep garrisons in all cities, which you probably should anyways, costs some upkeep but that's a cheap price to pay.
Conscription: +10% CS for all units. Gain a ranged unit, and another one in each city settled after picking this policy.
All around awesome. You now get the garrison-unit needed for Expansionism for free. Not only that but you have a slight CS advantage over people without Conscription. The free units makes a slight overlap with the Scaling bonus, making less use out of the production-bonus because you get the units for free.
Martial Law: Extra production in puppets and occupied cities. -15% maintenance for units.
Always kinda weird to have the last policy in a tree feel like the weakest one. Martial Law isn't bad, really, it just promotes a weird play-style. The lowered maintenance is always solid, no doubt about it. The production in occupied cities is only ever useful for building the courthouse, but that's fine. The production-bonus in puppets is okay I guess even if puppets tend to construct buildings just fine on their own, and that's pretty much all they ever do. I guess the idea is to puppet a city, let it build its buildings and then annex it and have it build a courthouse when it no longer have any useful buildings left to build. That makes a pretty solid foundation for your cities before you decide to annex them. Only real problem is that puppet seems to not actually want to build most useful buildings at all for some reasons.
There isn't really that much I would change about Honor, the policies all fit pretty well together. I'm not a huge fan of the play style you're pretty much forced into when you play Honor, but on the other hand there isn't really any other way to handle the expansion/military tree other than that. It's not like I tend to play completely peaceful or anything like that, I just don't like the game telling me what to do I guess, I like it being my choice when I rain fire and death down on my neighbors for placing stupid cities too close to my borders.
All above:
I noticed a pretty boring trend with the ancient era trees, and that's that the Finisher is generally really meh, all medieval and Renaissance trees have really interesting finishers. I understand that the ancient era trees are supposed to be less powerful, but they can at least have two effects just like all other finishers have.
I was going to include all Policy-trees in this one from the start, but after writing just 3 of them I realized that this is going to be a huge project and that I should probably split them into different threads, and also different days because now my head hurts. Good night.
Also these are all just my opinions, feel free to discuss and disagree and whatever you want.