I didn't really like it. But let me explain before killing me! *grins*
It was okay, but the director tried to put WAY too much in too short a time. He either should have made it longer, or took the trivial stuff out and focus longer on important stuff. I felt like I was watching the book on fast forward!
Otherwise, it was cool... The dementors were quite believable, I was impressed. I also liked how they did Buckbeak. :)