I play sinngle player. I am trying a PBEM game, but it moves at one turn per week. I tried a real-time lobby ty[e game but could never get into the game for real. I hage done a couple LAN games here at home.
Mostly I play late at night when insomnia/pain keep me up, so my scheduling is unpredicitable.
As to balance versus differentation, I didn't have an opinion strong enough to vote. As I type, I realize that I prefer balance, even in an SP environment, so that I can play different civs with similar levels of inovlvement and challenge.