The book was really quite good. The movie, however, is a slightly different story. This movie is a lot more “Hollywood” than the others with more silly jokes, forced character development, and over the top theatrics. There’s Hermione who must be hitting puberty, as she seems to be in a constant state of PMS. Ron seems a bit more flighty than usual. His older twin brothers have become cliched twin troublemakers. And, of course, Harry who is letting his status as supreme great wizard get to his head.
The formula remains pretty much the same for this movie, but it is markedly darker than the first 3. The kids are growing up, and they are coming across far more serious issues. The story is solid, and the effects are expectedly astounding. Plus, this movie marks the first without an extended Quiddich scene. And, in spite of the length of the book, this movie keeps the pace moving along without sacrificing anything too important.
I imaging the films will continue to get even darker. I also hope that HP5 will return to strong character development as well. 5 is the first book I haven’t read, so I don’t even know what to expect from it. I just hope we get through the series before the stars start balding or showing signs of wrinkling!
My Score: 3½/5

Yeah! What did they do to Flitwick?? haha, and what did he do to deserve it~ =P
One thing that has bugged me with the last couple of films is the fact that there’s now a new director for each movie; each with a different vision of what the area and landscape look like, how the characters act, and so on. Look at Harry Potter 5. I don’t know. I guess I like consistency in movie series. But that’s just me.
I’m not sure I agree with your statement of not sacrificing anything too important, but I did like the movie. As usual, the book was infinitely better.