I enjoyed it - they did a pretty good job of sticking with the book. The CGI was a little distracting to me...made me wish I coulda seen it as a twelve year old. But overall, well made.
I want to see it again at some point. I'm always a little bugged by pacing when I see a book turned into a movie - things *have to* move so much faster than they do on paper, and it's a little hard to take in.
I actually never read the book. All I have to compare it to is the BBC production in the late '80s, which was a multi-part series. I imagine the film is more professionally done.