They say that all the actors are loads better than in the first film and that the film overall is funnier and spookier.
The mystery reviewer also has good things to say about Kenneth Branagh as Gilderoy Lockhart, even giving him an outside chance of an Oscar.
The only bad thing about the film seems to be the same as the first one - it's too short to fit in everything from the book, making it seem a bit rushed in places.