Bright, witty, and absorbing. Yes, absorbing. I've read the reviews of this book which indicate that it's much too long, and that Harry is a brat. Yes, it is true, Harry at 14 has a temper and sometimes does irrational things. He's not perfect; he's an adolescent!
The story picks up again with summer recess, and Harry trying to find out if You-Know-Who is making himself known to the muggles of the world. When there is no odd news, it worries Harry even more. And he knows that his friends are working with others against You-Know-Who, but can't send him the information.
Things get very complex, but roll along quickly. These books are good because the world, Harry's wizards' world, has rules and stands on its own. One can visualize everything that happens, and know that it is all explainable in that world.
Even if Harry is a bit of a pain, I like this Harry better than the old Harry as he's more real. 14-year-old boys are not supposed to be perfect.