You can, I believe, measure the quality of a movie by the lingering memory you have of it. I’ve just been to see the Harry Potter movie, and in no particular order, remember the following,

The rustling and chattering of children, and the distraction caused by it.
The role of Hagrid as played by Robbie Coltrane.
The quality of the acting shown by Harry’s two sidekicks, and the lack of quality in the acting of the guy who player Harry himself.
Deja-vu after having read the book and played the computer game so soon before seeing the film.
The excellent effects.
Alan Rickman for his excellent Snape.

It was ok, good, not bad, fun, enjoyable, but it wasn’t brilliant, it wasn’t astounding, I didn’t leave feeling enthused. I’m not sure why. Go and see it, try and avoid a time when the kids are out, but do go and see it.