In the intro, Shusterman writes something along the lines of "I hope this is a terrifying, sleep-depriving book!" 
 Yeah, thanks Shusterman. 
 Yes, some of the new characters do feel a bit like those from Unwind, but I don't really mind more of them. And the one that's different ... well, let's just say that he's VERY different. 
 The best part has to be the plot. It's a bit hard to follow at times, but once you get it, everything falls into place and it's just perfect in its horribleness. If that makes any sense. Which I doubt it does. 
 Just read it, okay?