The movie in and of itself is a solid piece of work with a crazy cliff hanger ending. This is, of course, due to it being the first part of the 7th Harry Potter book we all know and love. As far as sticking to the book, it did well in a general sense. All the events are there, though slightly modified. I won't be spoiling any surprises, but I approve of most of the changes. They modify things from the book that couldn't be represented well in the movie.