I liked The Snow Merchant a lot but I think the real test of a children's book is whether a child likes it. It's not often they can be persuaded to write reviews so here's one on a 12-year-old's behalf.
My daughter took the book out of my hands the minute I finished reading it (having glanced at a few paragraphs over my shoulder). She liked the concept. All I've been able to get out of her since is that she likes it, meanwhile I find it lying around the house face down with an ever increasing number of pages towards the front.
Then she wanted to know what reading level it has because she thinks she has to read books at a certain level for school. It's quite a long book which has taken her over a week to read, for which she thinks she'll get no credit. I thought that was a bit sad. Very sad, actually.
I don't know what reading level it has. I thought it tackled quite a lot of thorny issues of identity, family and instability. There were times when it blew me away - but that's a mother's role - this will be clear to those who read the book ;)