I've given this one only 3 asterisks simply because I'm not that big a fan of Harry Potter in general. While it is an interesting story, it's just not my cup of tea.
Now, as far as a movie goes, it was pretty good. It starts out with some action, then slows back down to let you get a grip on what's going on. After that, it takes on the same pace as the other HP films.
The action scenes are decent, the special effects are wonderful, and the return of so many characters from the previous films, even if for a cameo, was interesting. The storyline was a bit confusing if you're not a reader of the books (which I'm not), so you'd be able to follow along better if you have read them from the beginning.
Overall, it was a decent film. A great family film.