As an avid Harry Potter fan, (of both the books and the movies) I was extremely satisfied. I have read Half-Blood Prince, and the rest of them well over 15 times each. I love Joe Rowling's world, and this is the first movie that really conveyed her prime themes and really followed the book.
What I was most impressed with was the dialogue this film. Besides a handful of patchy additions, almost all the dialogue was direct from the book, which I greatly appreciated.
All in all, I think this film sheds light on the writer behind the story and brings Joe's witty humor and dark prose to life like never before. As a devoted Harry Potter fan and director, I give this my delighted stamp of approval.