I was going to give this 4 stars, but then I started Nine Princes of Amber and I thought, "This...this is what 4 + star books are made of". So I'm giving it 3 instead. Don't get me wrong, Westerfeld has created a wonderful and well researched alternative history world. His novels are well written and his ideas well thought out. But, his books just lack something. They're soulless. I don't feel anything for the characters or for their situations. Sure the descriptions are detailed, the paragraphs properly edited and the characters well rounded, but it's just like a perfect looking meal with no spices or flavor. 
 As a whole, this was an ok series. I can see why people adore it as Westerfeld has obviously put a lot of effort to create Leviathan's world but it didn't blow me away. I'd have preferred some more emotional dialogue instead of endless descriptions of mechanical devices/animal devices and scampering across the Leviathan scenes. 
 This series was cute but I'm happy to finally be done with it. Would I recommend it? Not really.