K-mod's AI is the best available for Civ IV, but it comes packaged with some game mechanic changes, which are a mixed bag in my opinion. It maintains the original feel of the game for the most part. Culture victories take much, much longer though, since the free speech culture multiplier has been cut in half, the cathedral multiplier is nerfed, and most wonders and some buildings produce less culture. Great artist culture bombs produce 800 culture per era instead of 4000 regardless of era, so you have to get to the modern era to get the full value out of them. Also, religions can die out randomly in your cities from spread of other religions unless you're running free religion, meaning it's harder to build more cathedrals and/or you can't run pacifism for artists. Hope culture isn't your favorite victory.