Well I play on normal, so It usually lasts till the end without a winner, but ya sometimes someone can steal victory early
I'll probably be playing on Prince for this. It prevents the whole "I HAVE TO GET EVERYTHING PERFECT OR I WILL LOSE" rush you get playing on Immortal / Deity. I don't think Deity would make for a very interesting game, either. I won't get to faff about quite as much. :p
Songhai seems like a country that will become a global superpower in no time.
Yeah, Songhai basically starts steamrolling when they come across a few civs and beat them. I think the bonuses from gold tombs for pillaging is multiplied, too, so you a lot of gold as Songhai conquering Egyptians.
EDIT: I'll start in the morning, gents. I'm really tired at the minute.