4.5 stars, but I really had fun with this one, especially after coming off another book that rather disappointed me. I thought the world was a lot of fun, and I really enjoyed the characters. Deryn and Alek both seemed a bit young at times for their actual ages, but I liked them so much that I was willing to look past it. It's funny, because my current project is rather steampunk and takes place in a world with this kind of feel to it, so it was a lot of fun to see how Westerfeld handled it.
I'm really looking forward to reading Behemoth!