Not bad, but not the greatest, although to be honest I probably would have liked it more if I hadn't read it after Divergent, which was SO GREAT. 
 It's an interesting choice of society, however I didn't get the feeling that we saw enough of it. Maybe (hopefully ?) it will be explored in the next books. 
 Also another problem that I had is that I didn't really like the characters that much. For some reason, they didn't appeal to me at all. It's not that I hated them, just that I didn't relate to them or even feel anything for them. 
 The thing is, I'm having trouble explaining why I didn't like this book as much as I thought I would. So let's just say it's because I read it after a brilliant one.