
I'm really torn on this one. My eyes were glued to the page the entire time, but I was also irritated for the first 2/3 of the book.
How do I put this tactfully... The main character, Spin, is what I like to call a temper tantrum protagonist. She's obnoxious, combative, thick-headed, and profoundly, agonizingly immature. She lashes out, but not in a compelling way — her outbursts are so cringey that I was embarrassed on her behalf. And look, I'm sympathetic; writing hotheaded characters is difficult, because you constantly run the risk of alienating your audience. Sanderson just does not stick the landing on this one. By the time she improves, the damage is already done. Even the prose feels childish and clunky, like it's been contaminated by her inner monologue.
BUT. But. The story is very interesting, and I really, really like Cobb. The setting is intriguing, and the central mystery at the heart of it all definitely draws the reader in. The pilot training, which is clearly well-researched, calls to mind the Star Wars: X-Wing series by Michael A. Stackpole and Aaron Allston, which I loved. The dogfights were exciting, and there were moments of real emotional resonance. I'm going to read the sequel.
I guess what I would say is this: I've always felt like Brandon Sanderson is a good storyteller, rather than a good writer. At the end of the day, they are different skills. So, 2 stars for the main character and the awkward language. 4 stars for the world and side characters. Averaged together, I give it 

3 stars.
~*Mara*~ = ^.^ =
P.S. How does sunlight get in through the orbital shells? How is photosynthesis possible with the entire sky blotted out? Did I miss the explanation? Maybe I did. Maybe I was too focused on the fact that the male lead is called Jorgen. JORGEN. The Fairly Oddparents has ruined me.