Great game. We just finished ACT 1 in a group of 3. The combat and game play is a lot better (and the first one was good too). I think there are a few balance issues (reflect is really strong, and necromancer spells are incredibly strong), but that's just a small gripe. It doesn't really effect anybody else, so who cares. At least it isn't worthless like the first game.
I think I liked Cyseal better than Fort Joy though, felt like there was far more to do in Fort Joy, but I might have missed a few things. The rest of ACT 1 is better than the first ACT in the original game though.