Saw the movies, and didn't see much complexity there. I could be wrong, but it looks like Harry was born good and Draco born bad. Maybe there's more sublety in the the later books (Harry has trouble living up to his mission), but plenty of critics agreed.
Harold Bloom was pretty nasty -- probably too nasty, but other reviewers had a similar impression. I'm not saying it's horrible or bad for kids -- It's good that they're reading, and probably doesn't hurt them at all -- just that it's not the thing for adults.