I am surprised nobody commented on this so far. And also -- if people are saying that Mayan UP means like having no UP at all -- what about other tech bonus based UPs? Like Japanese and CHinese. At least Japanese UP shows "Modernization" in tooltip help, while playing CHina I don't see any "Nobody discovered this tech" tooltip in my science advisor, so I can't even see or feel my UP at all. And for a country like China current UP is even more unexciting than Maya's.
Current gameplay discourages building many cities for Chinese, because research rates go down and one cannot do anything. But look at these maps:
You can see that China always looks pretty brownish. Chinese people were remarkably low maintenance people, working hard while eating little and running effective administration early. They UP should simply halve all the maintenance, unhappiness and unhealthiness compared to other civs. In theory, CHina is the only DoC civ that can experience 5000 years of civilization.