I'm using Lusted's Battle & Campaign AI and i'm quite satisfied with it. I had many long-term alliances with the AI with it and enemies who got beaten up by me now accept peace and may even become vassals, too. The game get's somewhat easier with this though, because you don't have to fear unreasonable backstabs anymore... ;)

If you use it, make sure to read through the first 2 pages or so of the thread and look out for Lusteds posts, because complete installation instructions are scattered over his different posts there. Be sure to edit the ai_label of the muslim factions.

Link: http://www.twcenter.net/forums/showthread.php?t=138529