As a result, this is a tighter, more actiony, somewhat darker movie than the first. The first movie kept showing you whimsical uses of magic every five minutes, like The Flintstones kept showing you comedic prehistoric inventions. This one takes it as read that you know what's going on, what Quidditch is, and generally goes about the business of telling the story.
And good it is too. Much more fast paced than the book, and with good reason. The book subtly scatters clues here and there throughout, and it's a sharp reader that picks them up. In a film that's only 2 1/2 hours long, only a cabbage could miss them, so the mystery angle is played down.
All in all, if you liked the first one, you'll probably like this one more.
Couple of mentions: Richard Harris is less irrelevant in this one than the first, and is jolly good. Nice that his last performance is a warm, and charming one which reminds you why you always liked him. Kenneth Branagh sends himself up admirably. I've always though Dear, Dear Kenny to be a man who wallows in self love, and he milks it for all it's worth here.
Solid 8/10. 8.5 even.
Go see it. It's the only decent movie around at the moment that's not trying to mess with your head.
(NB: Do not see this movie at all if you are arachnophobia. *Lots* of spiders. *Big* Spiders. *Really* big spiders. Worth pointing out that in a 10 minute sequence they managed to get in the entire content of Eight Legged Freaks.)
Oh, and something else I should mention. The rampant Stage Schoolism of the first one is greatly toned down. Draco Malfoy, though, is still a kid who would have had a beating every day of his life in every school I ever went to. A smaller than average kid who goes around telling people he's better than them? He'd never have lasted the week at Birkenhead Institute.