I liked the movie very much, and it was very faithful to the book, though most of the byplay between the characters is missing from the movies and so they lack depth compared to the book. But like somebody said, definitely not a movie that one should let kids see on their own. I don't remember
ever being startled out of my seat in a movie before, but it happened this time, when the spider grabs Ron. There were other scenes too that were downright scary, or at least would be from a kid's point of view, I think.
And some scenes were in certain ways better than in the book, especially the one with the snake at the dueling club where it becomes public knowledge that Harry is a Parselmouth. That particular subsection of it owned the version in the book so badly it wasn't even funny.
MoO, the perceived logical discrepancy with Hagrid sending the kids to the spiders wasn't one, it was explained quite satisfactorily in the book (though not pointed out in the movie), and is especially underlined in book 4 where his past comes to light.
Thing is, those books need to be read at least twice, preferably three or four times, in order to catch all the little hints buried in earlier volumes. There are most innocuous things you never think twice about, then read a couple of later volumes and go back and WHAMMO!, it's like a bomb going off because you already know which evet is being referred to. E.g. See Chapter 2 of Philosopher's Stone and then Dumbledore's comments to Snuffles at the end of Goblet of Fire and see if you don't spot something... And that's not the half of it by far, just the most obvious example.
As for the prediction that Draco Malfoy will turn out all right later, I hardly think so, but that's my opinion, we'll see.

But it just doesn't fit. He's too cruel, too narcissistic and never willing to take any responsibility for any of his actions, too spoiled, and too selfish. Too much like his father, but with none of the qualities, most notably self-discipline and smarts, that make Lucius Malfoy so dangerous.
Edi