This was some of the best acting I've seen from several of the actors in this series. Some actors did fall short of the mark but it wasn't too distracting. The effects were good and fun to watch I would say there were only one or two gratuitous effects scenes. It was a lot funnier than any of the others somehow (maybe to break up the general dark mood of the story). There were lots of periods of laughing out loud in the theater. Don't know how closely it matches the book because I haven't read it several years now.
BTW this movie should have been rated PG-13 for violence and 'sensuality'.