I actually liked this a lot better than the His Dark Materials books - I've got the third one of those hanging about somewhere but haven't bothered reading it yet. I'm honestly not sure what it is that puts me off them, but something just doesn't work about them for me.
The third one is great, absolutely great - it is different from the first two ones, I liked the ideas behind the story, his idea of "death" and such. Very intelligently written.
I love the Sally Lockhardt trilogy, too! :)