By the time BtS came out for Civ IV, I had started playing on epic speed because I disliked how quickly units became obsolete; even though I wasn't much of a warmonger, it just seemed like the speed was better balanced (played mostly around emperor). I carried that habit over to Civ V, but now I'm wondering if that's really the best idea. I understand that Marathon is a huge advantage to the player, so I assume that Epic is also a serious boost. So have I been unknowingly gimping the AI? Should I dial it back to normal? Plus, with the speed the game moves at, Epic seems a little more like Civ IV Marathon.