Summary: An excellent enhancement to the original civ 5 game. The battles seem a bit more balanced, so you don't get the sudden unexpected a.i. enemy showing up at your down and wiping you out in a few turns as would happen frequently in the original release. Religion was also done quite well.
Summary: I should have gotten this a while ago but enjoyed the base enough and there is plenty to do so I never picked it up. Spreading religion changes the game so much giving more play options as well as spies.
Summary: This is a sold DLC addon with a number of civs added, natural wonders, wonders to build, spies, and the religion system. However lack of a religion win dampens the going heavy into religion and if you are leading in tech spies are useless. It's a fun addition but not worth twenty-five dollars unless it's just spare cash.
Summary: I now crown Civilization V and it's two expansions the best Civilization game ever made! This latest expansion is everything plus more. I do not have the time to write down here everything that all the others wrote so I will second what they say and add another BUY it!