I've seen the preair pilot, and although predictable it was very enjoyable. Good acting, cast, sets, and overall production values. The writing was as good as it could be given the constraints of having to establish characters and back story, hopefully this will improve as the series progresses.
One of the few problems the show had was with wardrobe, and if even I can notice this sort of thing it must be bad. The costumes worn by Mark-Paul Gosselaar look as if they have been torn straight from the back of Gregory Peck in "To Kill A Mocking Bird", someone needs to tell wardrobe to tone it down a little.
Also, in my opinion, the pilot episode focused a little too much on Mark-Paul Gosselaar's character. I think the writers would do well to give more attention to the other characters in future episodes.
I really enjoyed the pilot and think it shows promise. I will be watching any further episodes.