Well I finished the book this evening and must say I was very satisfied with this installment in the series. While the first book was primarily exposition about how Riggs' world works, the second takes those expectations and plays with them, setting them on their ear as it were in a few cases. Add in some moral choices to be made and the result is a more interesting tale in the telling. Still, some minor drawbacks though would be that at some points in the story the notion that narrative is picture driven looms unfortunately large. Also, Gymkata syndrome*, at least in the first part of the book, wasn't too far from my mind. By the last part though, I was much more engrossed in the novel by the end than Miss Peregrine's Home for Peculiar Children, and gladly give it a full four star rating, vs the 3.5 I'd given the first book. 
 *Gymkata being a martial arts film, featuring gymnast Kurt Thomas as the hero. Whatever the bad situation he finds himself in, there's always some kind of gymnast like gear close at hand to help him dispose of the bad guys.