The book is better than the movie. The movie was good in it's own right, but they could have done so much more with it. They shouldn't have deleted or shortened so many important scenes! You barely got to know the Cullins in the movie when in the book Bella interacts with them more and you get attached to them. :)
I think the only thing that TRULY bugged me about this movie was Bella's stuttering and "Heh" sounds almost every time she talks. Other than that, the casting was very good! :)