I don't know, the more I watch PoA, the more I like it. Cuaron did a great job directing, and though a lot was skimmed over and changed from the book, I find that it works well as a separate entity. And yes, the first two did remain true to the books, but then again those books were much shorter, and aimed more towards kids.
As a side note, am I the only one who hated the way Luna was portrayed in the film? It seemed to me like she was spaced out of her mind the entire time like she was high or something. And what was with that horrible grin she had on all the time? It made me cringe.
Edit: Also I forgot to mention that those bastards left out Dung. And Kreacher had two scenes in the entire movie, and played no part at all in the end. Anyone who's read the book would know why this was a horrible decision.