Yeah, the Persian UP is excellent, especially if you try to play a variant like this. I should have collapsed already.
The Mayan one? Meh, I guess they need something to compensate for their awful starting land and their somewhat... limited historical area.
Roman UP is great, isn't it?
If you gave the Mayan UP to Rome, I think that they would automatically win
The Khmer are quite good at science/culture, because of their ridiculous amounts of food.
The Malinese have an excellent UP, but very limited land
The Aztec UP is a bit underpowered, I think. You should be able to 'convert' units to your cause. Say you defeat an European Macemen, then you have a change to get a maceman unit.
What if you gave it to Britain?
I think that the mayans got it because they are pretty much the only ones who WONT automatically win... Well, maybe the khmer... The Mali special isn't bad either.
But they wouldn't know the knowledge crucial to making maces: BUREAUCRACY!!!
OK then, they could make maces, but they couldn't get THROUGH the bureaucracy