Doug Piranha
Warlord
I disabled culture for barbs because it was a major slowdown for whatever reason. That alone makes a game on a large maps with barbarian world option a few seconds faster.
The problem is that barbs build cities in spots that assume the city will eventually expand to the second ring: I just captured a city with garbage tundra tiles in the first ring, but copper, deer, and sheep in the second ring.
Does it even make sense for the barbs to build cities? The weak archer defenders are no obstacle at all once I'm ready to conquer them, and they are just a free city if well placed, or a bag of gold and +1 to the AC if not.