My guess is, that it's epic speed with the new 1.5 Factor for the AI bonuses. This is huge and it feel like one step higher in difficulty. My expirience is the same: Playing progress on emperor and epic speed with a non religiuos nation makes it near impossible to get a religion anymore without a lot of luck. Fighting unhappiness is very hard. Progress needs a buff anyway. Btw: Could anyone explain how the a/b/c bonuses work and where you can find the 1.5/3 factors for the gamespeed?