As a movie alone it is fantastic. Each minute brought something to the screen that made the movie just fly by. Some of the acting was stiff and a few scenes could have been either more drawn out (the climax) or explained more (Inferi) for those who have NOT read the book.
Compared to the book, it jumped around a bit, left out things that they’ll have to explain in DH: Part 1 and, again, the climax. The ending is amazing, however, and worth the wait.
It IS immensely enjoyable, though. I can't think of any of the other films that made me laugh so much, nor can I remember jumping the way I did (or even screaming!) at a terrifying moment! All in all, if you're looking for a film that is going to entertain the family, this is the one.