My opinion pretty much goes along with everyone else's, so I won't take time to write everything out. This was more a 3.5 I'd say. It was interesting in that what kept me reading was not necessarily everything that was happening (because the book felt like information dump instead of a really forward moving story a lot of times) but I had to know what the ending was that everyone was freaking out over! So the hype (anticipation?) carried me through. Lol. 
 But, really, my thoughts are pretty in line with everyone else's. So just read all the reviews below and you'll know where I stand with it. 
 (view spoiler)[ 
 Okay, totally not expecting Tris to die! Had to go back and re-read that part several times to make sure I read it correctly! But I do understand why Veronica did it -- it fits Tris' character arc. Just so sad! *cries* 
 (hide spoiler)]