Fairly random thoughts, really:
The book was quite similar to the film, in that there was only one section that I remembered being a lot different from the movie (and that might anyway be my memory): the opening. I don’t recall so much detail about Harry-getting-to-Dursleys, which didn’t surprise me and which I quite enjoyed.
It felt very much a first novel; there were some aspects of her writing style that had me wincing. That said, it was certainly readable. Obviously…
It is hard for me to say whether I would have been hooked on this had I read it sans-hype, and before seeing the movie. Possibly? Certainly the omnipresent threat of Voldemort, and the rather neat ‘one school year in a book’ timeline, makes a series seem attractive enough.
There weren’t that many characters in this book, and I think most of them made it into the movie. I know a friend of mine has a thing for Pansy, and I don’t remember her from the movie; there might have been one or two profs who didn’t make it into the movie either. Other than that, a good concordance I think? Also, I had forgotten how genuinely obnoxious Hermione was early on, and how little Harry and Ron like her at first.
This is probably one of the books where for me, having seen the movie was actually quite useful. I love Maggie Smith, so seeing her as Prof McG worked immensely well for me; ditto Robbie Coltraine as Hagrid. The banquet scenes etc probably also worked better for my limited imagination with something to remember.
Characterisation? Not that great. Plot? Not overwhelmingly original. Descriptive? Quite. Do I understand Tansy’s mania for fanfic? Not yet.