Saw Potter and I can only really say good things about it. I suppose if I try real hard I'll find some bad ones as well, so lets just see how things go.
First of all, Hogwarts is now a school, the children in it act like school kids, which is great fun to see, even if you're still in school. Secondly, the triplet can now act. I know they did act a bit in the last film, but this film is all out acting, and it's good. Humour has been cranked up a bit, many a time the audience errupted with laughter around me, which is all good. Effects are all out this time round, but not enough to overburden the story, which is also done well, if not a little surprisingly in parts as a lot of readers of the books will find.
The film in all is incredibly grown up, not all scenes are seen from Harry's POV like in the books and the dialogue flows nicely, it's not just giving us information anymore, but it now seems like the characters are living. The final act is done very well, inkeeping with the tone that the book laid down for the graveyard scene, all the way through to the credits, which, unlike the last 3 movies, don't arrive on a happy note as the film ends with the death of one of it's main (if not new to the films) characters. One little foible I do have is in the spoiler below.
The only thing that really got me is that anyone who hadn't read the books but had half a brain knew that Moody was infact Crouch Jr by around halfway through the movie, or at least when you finally see the pensieve scene and then is told that Polyjuice potion was taken from Snapes store cupboard. Now obviously, people who aren't familiar with the books probably would have forgotten polyjuice potion from the second movie by now, but it's still pretty obvious, whereas in the book, readers weren't given enough clues by half to figure it all out until it was too late and it worked a hell of a lot better then. Even if they'd did it gradually, it would have been good, but the movie seemed to make out as if he had something wrong about him from the off. Even still, all was good and done really well.
The ending especially will leave you more than a little teary, even if you have read the book and know what's coming.
So, basically, I'd give it a 4/5