They really molested the book severely. I'm not even a rabid Harry Potter fan and I cringed several times when I realized how they'd changed areas of the story. Several of my favourite parts of the book that I was looking forward to seeing on screen where huge let downs, such as McGonagall fighting Snape, and the showdown with Voldermort at the end. Any serious HP fan would have a seizure if they saw how they twisted the end into some duel between two magical titans. I kept thinking of Yoda vs Palpatine. Ultimately the end of the movie misses the whole point of why Harry defeated Voldemort.

As a movie its superb and very entertaining, but I couldn't help but feel a little flustered every time they changed something radically. Why not throw the diadem into the fiendfyre like what really happened? Why stab it with a tooth? Its like they went out of their way to challenge the book.

The best part of the movie was the revelation that Snape was actually good. They did that very well. Alan Rickman really is a great actor. As other have said, most of the greats were wasted, like Maggie Smith. I still consider Emma Watson to be an atrocious actress, but I think Daniel Radcliffe has serious long term potential as an actor.

I gave it 8/10, but it irritated me for the rest of the evening.