I know there are those who bemoan the absence of certain scenes and characters from the book - but this was not a concern for me. It's a movie, an artistic interpretation of someone else's work. I love The Wizard of Oz and don't feel the ruby slippers should have been silver, as they were in L. Frank Baum's original book. Rowling's books may be untouchable to some, but not to me. I have enjoyed reading (and re-reading) them, but I am not blind to their flaws. I love the HP universe and the characters that inhabit it, but apart from the first and possibly the second book, they could have all used a brave(r) editor. In fact, a lot of red ink was called for. Do they still do abridged versions? Her plotting, although ingenious, is over-done at times, characters and situations over-explained. The repetition of some motifs (the prerequisite Quidditch match, the opening scene at the Dursleys, the endless battle-scenes) became too repetitive.
I actually appreciated the opening scene of HBP which had 16-year old Harry flirting and trying to pick up a pretty waitress. It effectively made Harry real, and young, and hormonal - all aspects that were treated very clunkily by Rowling in her books, I'm afraid. The movie portrays the young wizards' coming-of-age through their early romatic experiments, as their more serious coming-of -age, the shadow of adulthood, responsibility, and the threats of an unsafe and insecure world, Rowling's major plot elements, hover ever closer.
[Romilda Vane and Harry are staring at each other across the library]
Hermione Granger: [snaps her fingers] Hey, she's only interested in you because she thinks you're the Chosen One.
Harry Potter: But I am the Chosen One.
Hermione Granger: [smacks him on the head with the newspaper]
Harry Potter: Sorry... kidding!
The film is simply wonderful to look at. The Death Eaters chase through the field is brilliant. Hogwarts hasn't felt as visually real to me since the first movie. I have enjoyed the "stunt casting" of some of my favorite British actors Kenneth Branagh, Brendan Gleeson, Gary Oldman, etc. in previous films, but this movie's newbie Jim Broadbent brings something extra-special to his role as Professor Slughorn. He fits in seamlessly with the cast, as much as a comfortable armchair...
The younger actors really shine too, especially Daniel Radcliffe, who has made Harry a strong, even obstinate at times character. The scene where he comes across a sobbing Draco, also played wonderfully by Tom Felton, was true to the characters while also making the audience (or at least me) cringe a bit. Harry has no compassion for Draco. He is always angry, suspicious and on the attack. Not that his suspicions aren't valid, but where is his empathy? It brought back the earlier scene of Harry caught spying by Draco on the train. Both boys behave badly, as teenagers are wont to do.
Draco Malfoy: [looking at Harry's broken nose] Nice face, Potter! [Harry nods disdainfully; Luna pulls out her wand]
Luna Lovegood: Would you like me to fix it for you?
Harry Potter: Um... have you ever fixed a nose before?
Luna Lovegood: No. But I've done several toes, and how different are they, really?
Harry Potter: ...Okay, sure, give it a go.
Luna Lovegood: Episkey! [a loud crack]
Harry Potter: Augh!... [rubs his nose gingerly; looks at Luna]
Harry Potter: Well? How do I look?
Luna Lovegood: Exceptionally ordinary.
For teens the world can be black and white, with no gray. For Harry Potter, the world and the film, gets progressively darker. And thanks to cinematographer , beautifully so.