I am playing Japan. Top civs are Mongols, India, Russia, and Songhai. Mongols and I are advancing crazy fast. And the Mongols have 19 cities and -18 happiness. The City-State surrender ability keeps going off, more than half their cities are city-states.
Immortal difficulty, 22 civs, Huge Earth map. Standard Speed. Only mods are those in your mod pack plus InfoAddict.
I popped a really lucky faith goody hut early on, so I managed to grab the Path to Transcendence belief, which is amazing. It's like a free tech, free policy, free golden age, free Great Prophet, and a pile of gold each era.
Something else I noticed in this version: The AI is spamming forts all over their borders. But they're not keeping any units in the forts, so they're not that useful in defending against a prepared invasion.