If I saw this movie without ever reading the book, I would be confused with what was going on in the plot.
Myself, having read the book, I am disappointed with a lot of the decisions made as to which plot lines to cut vs. what to keep in. Also, the film's climactic scenes were not exciting. My favorite scene from the book turned out to be a fast 1min CG that left me feeling unsatisfied. Not the best HP movie for sure.