I'm halfway through Philosopher's Stone. It's very readable. The style and storytelling are sometimes clumsy- but you're swept along by the stream of invention. Clever things come along at the rate of about two a page. Even though I've seen the films, she's got me wanting to know what happens next.
I miss Alan Rickman. The written Snape is just a mean old man with a hooky nose; nothing sexy about him at all.