Disappointing for all but a few...(possible spoilers) Yes, the movie was fast paced; yes, it held my attention; yes, it was more mature than the first two. That said, it was sadly disappointing.
I've read all the books and saw the first two movies. I went to this movie with two children who saw the first two movies, and their parents, one of whom knew nothing about the books or the movies. No one but I understood the movie. No one could follow it, beyond the surface story.
Too much essential detail was left out, evidenced by the questions I heard afterwards: What are the dementors doing when they do that sucking thing? Why did they keep going after Harry and not the other students? Why didn't Harry get in trouble for zapping Snape? Why did Sirius Black break out now? How did they know which animal was involved? What happened to Trelawney? Why didn't McGonigle know what was going on? More important, why didn't Snape know what was going on??
On a different level, why not a bit more attention to making Dumbledore look more similar to Richard Harris? A little more hair, a little more beard would have done wonders. No, that might not matter to adults, but it matters to children!
I can only hope that a Director's Cut exists, and that IT will be what's on the DVD when it's released.