Which one is better in your opinion? When I first played KH II and got halfway through beating it, I thought it was ten times better than the original game and back then when I first played it, I hadn't played KH in a while. Now that I'm replaying it and just defeated Ansem/Riku i'm starting to see that this game is better in some respects, like the level designs, way more platforming elements than in KHII which has barely any at all. Also it just have a more nostalgic feel. The difficulty is better than KHII as it felt both on normal and Proud mode easy as pie, while Expert mode on KH you can really feel the difference, I never lost to Malificent Dragon so many times. The arena battles are a little better too and lengthier you really didn't get the same feel from the arena matches from II than the massive Hades Cup in KH and don't mention the victory dances which are screaming with FF referency goodness.
Actually I think i like KH better. KH II is all about flashiness and trying to be gangsta with all those reaction commands.