As someone who has never read the books, but enjoyed the other filmed Potters, I was disappointed with #4.
The biggest problem was the pacing: I found myself loosing interest pretty soon after it started. Not that I ever really got bored. Just that I had a hard time caring. Something about the acting (more likely the directing) didn't "sell" me. Plus, the story arc was weird and hard to make sense out of. No matter how good a book is or how faithful you want the movie to be to it, a film must stand on its own terms and be true to its own world. Harry Potter 4 fails on both counts.
Also, some of the music was unbearably cheesy ("prom scene" and closing credits).
The biggest problem was the pacing: I found myself loosing interest pretty soon after it started. Not that I ever really got bored. Just that I had a hard time caring. Something about the acting (more likely the directing) didn't "sell" me. Plus, the story arc was weird and hard to make sense out of. No matter how good a book is or how faithful you want the movie to be to it, a film must stand on its own terms and be true to its own world. Harry Potter 4 fails on both counts.
Also, some of the music was unbearably cheesy ("prom scene" and closing credits).