As has been said before, this is a really bad Harry Potter installment. Just viewers can throw away Star Wars-Episode I and not miss anything, this Harry Potter film does not have to be purchased and you will not miss anything.
This is actually the first movie that I have ever been to where a person near me was actually SLEEPING through most of the movie. Yes, SLEEPING. And snoring. It became actually funny and it slowly sunk into my mind that this movie was a huge load of crap. If you have never read the book, you would be totally confused; If you HAVE read the book, you would not only be totally confused, but you would be really angry that all of the MAJOR PLOT POINTS of the book have been left out.
This is a very important lesson for you aspiring filmmakers and screenwriters. Story is king. Story is king. Story is king. Let that stew in your brain before you ever write anything again. Now I don't want to totally eviscerate the screenwriter, Steve Kloves. He has been the screenwriter for most of the series and, so far, has done a pretty good job of converting huge novels into entertaining scripts, so the fault has to lie with the director, David Yates. HP:OOtP was his first HP movie and, at the time, was my worst one. I thought then that the book has been done a disservice. Now my fears are totally realized when this steaming heap of crap came out. It seems to me that David Yates took the screenplay, and said, "I want to compete with all of the other teeny movies out there, so out go major plot points (teens don't go for all that plot and thinking stuff anyways) and in goes more moody swoon y teeny pablum. After all, I AM the director." And there, dear aspiring filmmakers, is the when someone needs to take a good piece of hickory and break it across the front of your face, leaving a "Louisville Slugger" logo imprinted across your face. Because, YOU screwed up.
Now that we have the same two teaming up again for the last movie, get out the Pepto.