The Republic at War AI is very aggressive and active, keeping you on your toes. The AI here is very easy to beat, so people should have no problem on moderate or easy difficulty. Overall in the actual battles themselves I think the AI is alright. It will only rarely attack your planets, and when it does it might not have enough troops. In the Clone Wars mod Galactic Conquest, the AI is very passive. Unfortunately, the AI in both games have some problems.
The first mod, and my favorite of the two is the Clone Wars mod.