Somehow it seems to have become a law of movies based on best-selling books, that they have to make ridiculous and pointless changes to the action scenes in particular, to make things look flashier (though at times it's hard to see how the change is any flashier or more spectacular than the original plot). Which leaves you with movies that look gorgeous, may well have fine acting, and excellent scenes in the calmer and more intimate parts of the plot, but disappoint in most of the action scenes.

The first Deathly Hallows movie had not that many action scenes, even had the odd deviation from the book that actually worked (yes, I'm thinking of the dancing scene), and took its time to tell the story. This one just went back to all the old flaws of the series - rushed plot development that becomes a bewildering mess to those not familiar with the books, and pointless and silly changes in the action scenes. Not really surprising, but still disappointing.

I'm kind of tempted to say that they either deviated too much from the books, or too little. All of those later movies (except DH1) might've been better with still more secondary characters and plotlines cut, so that what remains is less messy and not completely incomprehensible. As it is they end up with a plot that fails to satisfy anyone - the book fans are annoyed by all the changes or omissions of their favourite scenes and lines, while those who haven't read the books simply don't have a clue what half of all that stuff is about.