I thought the film was very good. It deviates from the book in multiple ways, but that’s pretty unavoidable. One aspect I found slightly humorous is that there is barely a nod given to the fact that the characters are attending a school. Harry has a potions class and ... well, that’s pretty much it.
I agree that some deviations are necessary. I didn't understand the scene with Bellatrix and Fenrir Greyback attacking the Burrow, though. What do you suppose was the point of that?