I won't say much more than this: Enjoy it for what it is.
Don't dissect the movie apart and compare it to the book, what was left out, what extra was put in, what changes were made, etc. The book was 734 pages long. To be true to the book 100%, the movie would have had to clocked in at 5 hours or more.
It's a film ADAPTATION. Appreciate it as such. If you're one of those people who will say "Heeeey, in the book Hermione's dress robes were BLUE ..." don't go see this movie (or at least don't come talk about it here because I'll help someone drag you out back and shoot you).