Hi
I think a lot depends on play style and preferences. I do not find Russia a a weak civ or even a bad civ at all.
Honestly, I actually get MORE use out of Russias uniques now than I did before BTS. I tend to like both Spiral Min and Angry Wat and usually do my best to get those wonders one way or another. And if I do especially if I have both I HATE obsoleting them. As a result I avoid computers as long as I can get away with it. Before BtS it would mean if I was playing a game to the modern age I would hardly ever use Labs. But now I actually get TONS of use out of Labs now that I can get em without computers. So rather than the BtS change making me less likely to use Labs it actually makes me more likely to use em and to use em for longer period than I would have before.
Leader traits being nerfed is another matter of perspective and taste. Personally I find financial to be annoying. I know there are MANY who will argue that financial is the best darn trait in the whole game and the most powerful. It may be all that but for me it's still annoying. Mainly because I just never feel I am getting all I should out of financial unless I have at least SOME cites that are cottaged as heavily as possible prefferably on heavily rivered/floodplains. And I a HATE cottages. Esecpially heavuly cottaged cities. They take waay too much work for me. They take forever to build things and take forever to really get going. I would rather farm, watermill, or woodmill those squares. I like big production cities like half the city farming and the rest mining or cities with lots of people/specialists. I also HATE when a town gets pillaged/sabotaged or just lost through event or capture or a culture push or whatever especially when it is at a point in game where there is no time for it to ever really get back up to where it was. The way I play I tend not to use those civics that give benefits to cottages/towns so again I am always annoyed at feeling either I have to use civics I dont prefer or not get the most out of my cottages. And this is probably the LEAST of the annoying things about cottages as in it doesnt happen EVERY time and even if it did it isnt the MOST game impacting of them but just for me it happens to be the BIGGEST annoyance. And that is when it gets late into the game and the ONLY $^%*^$^%* plot of oil or uranium or some important resource I really want appears under a town I taht has spent hundreds of turns growing. So I have to plow it under myself. I HATE that. I know it's not rational but it BUGS me. It's just not as bad if I have to plow under a measly farm or watermill or something else as a town that took FOREVER to get going.
So when Cathy got her traits changed it wasn;t a nerf to me. Imperialistic? no not the strongest trait in the game BUT quick settlers ARE nice at the start AND GG's are FUN and imperialisitc means I can get more of em. So for me Cathy went from an annoying leader to play to a fun one. And BtS made it even better. I LOVE when I have a chance with an imperialistic leader to just surround some bacwards Civ with privateers and pump up peacetime GG points by sinking triemes and caravals hehe

. So from my perspective instead of "nerfing" Cathy those changes from Warlords and now BtS are BIG improvements. As 4 Petey and JoJo well Petey's traits never did thrill me and I actually like agressive/industrius and BtS never really changed them much one way or the other.
Now the UU. I dont see anything wrong Cossacks. Do they dominate their era they way Prats can? No not anymore. But I think that is kind of the intent. Not EVERY UU is meant to be THAT dominating. And just because a UU isnt so powerful that if you get it then until the next tech age ALL you have to do is ONLY build that UU doesnt mean that UU isnt any good or that it isnt better or more useful that the unit it replaces.
ALso it seems to me that most and maybe all the criticisms of why Cossacks are "meh" now isnt really criticsim of cossacks in spefcific as much as criticism of Calvary in general. And again that is all just taste and persepctive. The way I tend to play if I am waring and have a big lead I usually go with mounted warriors especially if I am playing the persians. So I tend to have LOTS of Knights Currisars by time I get rifling and the upgrade cost from currisar to calvary is if it's not THE cheapest it is definitely on the VERY cheap side so it reallys is no big deal at all to AT least quickly upgrade your highest promoted curriasrs if not all you have very fast. And it is definitely waaay cheaper than massive upgrade of macemen or whatever to rifleman. I am not exactly sure what the cost is for musketmen to rifleman but for me even playing on marathon and the new changes to BtS I hardley ever make many musketmen if any and even if I do they are usally CG promoted defenders and not the best choice for upgrading as say CR3 mace men.
On other hand if I am NOT warring much and just turtling/buiilding I still avoid riflling as long a spossible becuase it means I want to milk my castles as LONG as I can so I am still relying mostly on Knights/Curisars as the bulk of my military. maybe just one big stack or a couple of medium ones to quickly go help out anyplace that is under threat instead of having been pumping out mounted units like they going out of style but either wway if you count "efficient" as what you get on the field the quickest and easiest. 90% of the time a mass curiasser upgrade will have me at least ONE decent size stack of calvary cheaper and quicker than I could rifleman.Plus I dont have to worry about keeping as much gold to get the same number of units and I dont need to stop all my cities or ANY city really to change production on rifleman. And to me efficent isnt JUST the gold or hammers a unit requires it also how fast they can get the job down. I like to play huge maps so that double movment does help. On defense they get to trouble spots MUCH faster. And on attack if say this late in game you are taking out a 10 city civ two turns faster per city, getting a war over 20 turns quicker to me is very much worth it even if it means a few calvary units get sacrificed softening up a city so it's easper for the rest of the stack to clean up the wounded even on marathon.
And if the tech level is so close that I am facing cities defended with riflemen having calvary is still effiecnt since Calvary scout out faster, pillage resources quicker, steal workers better in between moving from city to city and usually NOT every city is going to be overloaded with anti cav units especially at the end so if/when you see that easy pickings city you can get it overun quickly if you have some calvary in your stack along with rifles and trebs or cannon. So at least for the way I tend to play Calvary are very very useful and effcient. And since cossacks are are still stronger than normal calvary even with their drop in str from 18 I have no problems with that.
But yeah that is just me. But here is one thing to consider. If someone enjoys using rifleman and likes to go for them asap more my question would be why are you worried about Russia when you should be playing Britain? hehe

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I mean not EVERY strategy is best suited for EVERY civ. I think if someone says something like "If I play this way which I usally do and do it when playing this civ it really isnt any different from any other civ so it needs to be changed. My answer is kind of like well I think part of the intent is you really arent intended to play Russia like any other civ. You play them like Russia. Russia has some very strong aspects and if you play to them they can work VERY well. If thats not the way you like to play then maybe another Civ has different strengths that are better suited.
It is like when some people mentioned not enjoying late game UU/UB like Malls. Just because they come in late doesnt make them weak. Yeah I know many people who say things kind of like "well for me if the game isnt won before gunpowder then I wasnt playing right" So for that player pretty every civ with a UU/UB that doesnt come in until after gunpowder is useless. So for that player who usually ends their game by gunpowder playing the Americans would be almost no different than playing the Germans. That doesnt mean the Germans and Americans need changes. And it doesnt mean that person is not playing right. Or like how I dont enjoy financial and HATE cottages. That doesnt mean financial and cottages are useless or that changes are needed. It just means thats not really the best trait for me to play.
Not every Civ can be equal. Well I guess they CAN be 100% equal like in civ2 and yeah I loved civ2 but I think the way it is now is MUCH more fun. I think yeah that means maybe some civs or some traits are gonna be more powerful than others. And some strategys are gonna work SUPER with this civ and be "meh" with that civ. Even situations can change how strong a civ or strategy or whatever might be. I mean if you enjoy random maps/civs type games well sometimes you might get Rome on islands or the the dutch starting out in the middle of a pangea. In something like that yeah the game maybe "meh" or even downright sucky but I honestly think that is the point.
And I also think in terms of changes made and how they affected Russia. I wouldn't call Russia overnerfed even if they have been nerfed the most. In other words maybe they have been WEAKENED the most from certain perspective but even giving that point they are still not even close to the WEAKEST civ in my opinion at least. Especially when you try to work their strengths as much as possible.
Well sorry for the long post but thats what happens when you have a cold and stay home from school and are bored hehe
Kaytie