I preferred everything in KotOR 2 over 1.
More feats and force powers, more ways to approach situations, much better choices an consequences, better writing, better characters (HK factory is just an awesome moment), etc... Also KotOR 1 is surprisingly a terrible PC port and has crashed three times as much as KotOR 2 so far, and I'm not even halfway through the game.
The problem is KotOR 2 is only really great if you have the restored content, which I tried and it frankly adds a lot to the ending.
And no rak'ghouls. /facepalmDo you have an ASUS card? They didn't make the game compatible with it's drivers or something and that caused crashes.