The HBP film doesn't have the subtleties of the book in describing the main characters' unfolding love lives and it deviates from the storyline quite considerably. The books have a lot of plot and fitting them into a feature length film is always going to be difficult. Nevertheless, HBP focussed on the rom-com elements of the story and excluded critical elements such as the Gaunt family and an explanation of why Harry had to return to the Dursleys' each summer. The ending achieves the same result as the book, but deviates unnecessarily. If you have read and enjoyed HBP, you won't be impressed by the film version.