Tradition is good for late-game.
Liberty is good for REXing, but crap for anything that isn't pretty much max ICS late-game.
Honour is a nice second tree for conquest, or for Songhai/Aztecs.
Piety is cool for culture or for ICS (half price shrines with Asceticism is always cool).
Patronage is a nice second tree if you have to take a policy or two before hitting Rationalism.
Commerce is a great on water maps, kinda crappy on anything else, other than Protectionism.
Rationalism is extraordinary. No more needed.
Freedom is good for culture.
Autocracy is good for domination on smaller maps.
Order is another tree that is just amazing. It's not that Freedom or Autocracy are bad, per se, but Order is just so much better.
Actually, it's the other way around if you consider domination games. Sure, tradition is good, but liberty outshines it in the long run: in a 20+ cities game.
Let's assume your average city size is 8 population. That gives 8 bonus happiness (5% discount from 160 population in 20 cities) + 19 happiness (+1 happy per trade route) = 27. You would need a size 54 capital in a tradition game to compete with that.
Also, free monuments are nice, but representation will be at least equal in power, when you start annexing city after city and buy science/culture buildings there.
That said, I had both successful tradition and liberty domination games on deity. Lately, I favor the latter tree more and more.
Let's assume that each of your cities grows 2 more pop, giving you bonus happiness of 20 from Aristocracy, compared to Meritocracy's 20 (you get one from your capital, too). Meritocracy also give you -5% unhappiness, too. At 19 cities * 10 pop, that's 9.5 happy. Raw, that's a size 19 capital for Monarchy to outstrip Meritocracy. +0.95 happiness from Meritocracy, means it still beats Tradition. At 20 pop, that's +1 from Aristocracy, meaning that's where it hits neutral. Size 20 capital is not uncommon. T-Hawk did a much more advanced look into Tradition vs. Liberty
here. Tradition beats Liberty, even in happiness.
Also, just so you know that he isn't just a die-hard Tradition fan, look
here for a T183 SV by him as Korea with Liberty. He beats that in two subsequent attempts with Tradition with T182 as Babylon, and T171 as the Dutch.