I really liked this book, even though the movie is still better. My kids kept asking to see THIS movie, and I had to explain that this one doesn't exist. It is COMPLETELY different, other than the general name of a couple of characters. Parts of it are really clever, while parts of it are just plain silly. Obviously, my kids preferred the silly and I, the clever. It was a good balance. 
 The language was a little mature for my kids, 5 and 7, but they really didn't seem to mind. I figure it's a good introduction to bigger words. Probably a good read for ages 8-10.