8/10. Not as good as T2 (but frankly, that would be nearly impossible without James Cameron) but definitely a good addition to the series. I thought that the humor was alright, a little campy but definitely smile-inducing. You don't agree? Talk to dah hand! The action scenes were excellent, but not as calculated as T2's. If you put a perfectionist (read: James Cameron) behind the wheel here, I think that this already solid aspect of T3 would've been even better. BTW, pacing.. too fast, movie should've been a little longer with slightly more intellectual time. (might create problems with T4, though.. see my next paragraph)
As far as storyline, I thought that they did a fairly good job.. and left plenty of.. well, not plot holes per se.. more like plot ambiguities which would be major parts and twists of the story in a T4 if they made it.
Acting? Arnold kicks ass, this is easily his best action role since Eraser if not True Lies or heck, T2! At 55, he looked great and had a big presence.. albeit he was a lot better in T2. Claire Danes played her play pretty well, but I thought that Stahl was so-so. He did some things very well, and other things.. meh. I'm not sure if Eddie Furlong would've done a better job.. maybe, maybe not. Kristanna Loken did a commendable job. Sure, she only had a handful of lines (reminiscent of the T-800 in T1) but played the part very well (almost as good as Robert Patrick's T-1000, almost) and her presence was great. A good villain, definitely.
Audio was a mixed bag. The music sucked (they even kinda botched the credits theme) but the sound effects were great.
Ilfirin: Just a note, AFAIK the T-1000 can't fully regenerate from one small piece of itself. (unlike other characters, such as DBZ's Cell) He has to have most of his body readily available.