@Grungeking Unless you're playing Fairy. Then they're absurd in a very different way. And once you get into the really high level upgrades, your neutral buildings will actually be outperforming your low level alignment buildings simply because of the larger bonuses per upgrade.
@jodoninja While I agree with most of what you say, you're really underestimating the lategame potential of Angels. CtA+the Angel faction spell offers a massive multiplicative boost that can then additionally be taken advantage of by using Tax Collections. The number of spells needed to be cast per game is also VERY reasonable and it's not unusual for a semi-active player to reach 200-300% bonus by the end of their playthrough. Angels are probably the most well designed faction in my eyes, working exactly as they're supposed to and proving extremely effective.