As always, I will divide this review into two sections. The top portion will be spoiler free. Everything after the SPOILERS! mark will be, well, full of spoilers, and I'd assume the comments will be as well.
Going in to this film, I was worried. I had heard many good things about this adaption, but frankly, I wasn't convinced they could convey the proper tone for the book. Sure, Harry Potter 1 was all magic, smiles, and laughter, but things have progressively gotten darker and moodier. For me, Goblet of Fire, almost stands out as the Empire Strikes Back of the series. It's the turning point where the laughs kinda die off and the body count begins. What I love most about the series is that it goes from light-hearted magical fair to a much more serious, emotional, and frankly, painful story. To Rowling's credit, she never turned the book "adult." There isn't sex, gratuitous violence, or other cop outs. Rowling moves the series expertly along as the characters age and the stakes rise.
So back to my worry. The books convey this pain, this fear, so well, and I wasn't sure the movie could pull it off - especially the pivotal ending. Happily - they did it. Obviously a lot was cut out. But I think the movie did a fair job of striking a balance between length and representing the book. This movie is sad. Overwhelmingly so. And I'm happy they kept it like that. There is no "Hollywood" cop out here.
If you are a fan of the series, and maybe felt a little let down by the last movie, definitely see this one. It's worth seeing on a big screen. You may not want to bring your youngest. I brought all my kids, and while there wasn't anything objectionable (even with all the teenage hormones), the movie may drag a bit for them. Again, it's more dark, more serious, than the previous ones.
To me, there are 3 critical parts of the entire series. The death of what's his name at the end of Goblet of Fire, the death of Dumbledore, and the revelation of Snape at the end of B7. I thought Snape's history in Order of the Phoenix wasn't handled well. But they handled his character great here. Ditto Malfoy. The movie did a great job conveying how tortured he felt.
The scene with the bridge in the beginning was incredible. It was a great way to demonstrate how the Muggle world was being impacted as well.
I do wish they had spent a bit more time on Voldemort's past. They didn't do a bad job - that young kid was perfect (remind anyone of Damien or the Omen or whatever that old movie was?) and I wish they had maybe cut a bit more of the teenage hormone stuff and spent more on him.