I watched Scream 3 last night and really enjoyed it. I still think it is better than Scream 1 & 2 but it's not that much better. They're all really good.
As for the characters, I didn't really care that much for them, especially the new ones. The only people I seemed to like were Sidney, Gale, Dewey and the actress who played Gale in Stab 3. The rest I didn't really care about.