Maybe you are right, but I think that if I hadn't read the book, I still would've left the theater disappointed. Sharli didn't read any of the books, and she felt the same (and she tends to be much more appreciative of movies than I am - I'm just plain picky).
I feel that they could've improved a lot. For instance, I found the editing to be quite weak, which made certain funny moments less funny.
One point where I do have to compare the movie to the book is the part where Snape is teaching Harry to shield his memories. In the book that plays a major part, and Harry does not use the spell against Snape. I don't want to go on about little details, but I'm making a point here. The point is: neglect of previous movies.
Perhaps you remember in part 4, Dumbledore takes out a memory and puts it in a basin of white ribbony other memories? Harry finds a similar basin (Snape's) and that's how he gets into his memories. What he finds out about his father is much more shocking that way, I believe. There are some other parts that didn't really come back, where they made an effort in the previous movie to emphasize it.
Oh well... It's not all THAT bad, but people who've read the books pretty much all feel the same way. Since the same director is going to do part 6 as well, I'm not going to go with such high expectations (I found book 6 to be the best in the series).
