This film picks up right where its predecessor left off; Dumbledore is dead and Harry, Ron, and Hermione are preparing for their quest to find and destroy the Horcruxes which are keeping Voldemort alive. Events in the film gain speed as it progresses and reach a quite frenetic pace after the fall of the Ministry of Magic. This fast pace suits the film well, as it adds to the tension which we in the audience are meant to feel.
The film comes off extremely well in comparison to the book. There are two main reasons for this; the first is that there are events in the book which, when read, are fairly monotonous. The film however, is able to show these events rather than tell them and the pacing of the story is improved because of this. The second reason is that the book does not fully explore the emotional journeys of all the characters involved. The film is able to explore these journeys because having actors depicting these emotions on screen allows us an insight into characters besides Harry himself. The film’s ability to show rather than tell makes it a substantial improvement over the book, and showcases the brilliant work of everyone involved.
That said, the film is not without its problems. The largest problem is one of accessibility. There are many characters, places, and things in this movie which were introduced in previous films and so do not receive a new introduction in this one. Obviously, this movie is intended as part of a series and as such can be forgiven some of this, but it is a noticeable issue. The second problem is one of intended audience, because when Rowling was writing the books upon which these films are based she began by writing what is essentially a children’s story. However, as the books developed more mature themes made their way in – with the result that the final books in the series are actually quite dark. This progression is mirrored in the films but its effect is heightened because the films show events rather than telling them; it is one thing to read about Bellatrix torturing Hermione, it is quite another to see and hear it.
These minor problems aside, this is an excellent film and I would recommend it to anyone, so long as they've seen the previous films in the series.