I'll begin by saying this--as a Harry Potter fan, you MUST separate the books from the movies. If you step into that movie theater expecting a chapter-by-chapter replica of the novel, you will walk away disappointed (I guarantee it). I have approached every movie with an open mind and have understood that it is just impossible to translate every bit and piece of the novels. J.K. Rowling, being the literary genius that she is, has such a complex and intricate map of the wizarding world in her head. We get to read some of it in the Harry Potter books and we get even less from the movies. Would I have loved to see the Dumbledore/Grindelwald relationship in the movie? Yes. Would I have enjoyed to see Remus and Tonks' relationship developed? Yes. Would it have been better for the movie to include every single plot line, character, and twist? Probably not. At 130 minutes, Deathly Hallows Part 2 is the shortest movie of the 8 and it still leaves major aspects of the book out. But it was what had to be done to make the film the best it could be.
The film is everything you want it to be. You will laugh, you will cry, you will be squirming in your seat and anxious (even though, for those who've read the books, you already know what is going to happen). The cinematography is astounding, as well as the special effects and, at the end of it all, it's incredible to see how much the cast has grown up. If you take the movies as they are, you will be more than satisfied. It is like graduating college; you've been with Harry, Ron and Hermione from the start and understand that it is time to let them go. If you haven't seen it already, do it. And bring a box of tissues!