A well-written page-turner with a strong female lead. However, while it is entertaining - particularly the first third - it lacks the originality and emotional pull of other dystopian series openers such as The Hunger Games or Ender's Game. 
 My take: 
 Roth's triumph is Tris: a strong female character who gets on with defining her own destiny without being too annoying and whiny (alright, she does whine a bit, but it's mostly justified). You care what happen to this girl and follow her willingly as she leaves her family to go through initiation into another tribe. However, for me, the book lacks the emotional intensity of The Hunger Games. There are no moment's comparable to Rue's death, for example. When [SPOILER ALERT] Tris' parents are dispatched swiftly in the final pages of the book, I shrugged and read on. We hadn't spent any time with these characters and it was difficult to feel sorry for their passing. This leaves me worried for the next two installments of the trilogy; with only Tris to really care about I don't know if I'm invested enough in the story to stay with it for two more books. 
 The idea of dividing society into a series of factions is a well-established idea seen in a lot of dystopian fiction. Unfortunately, here I felt the divisions over-simplistic and difficult to swallow. 
 Don't get me wrong, overall this is a good read (and merits its many 4/5 star reviews). Apart from a bit of slack in the middle (when initiation training starts to drag on - a problem Ender's Game also suffers with), it rattles along at a great pace, leaving the reader little chance to get bored or distracted. 
 Now to see whether Roth can sustain the interest over the remaining two books...