The first problem I had is the lack of back story. I realize the book is already 525 pages, but Veronica really needed to reintroduce the secondary characters. After waiting a year between reading Divergent and starting Insurgent, I had forgotten how several of the characters fit into the story. I was able to piece some of it together, but ultimately had to reread a few chapters in Divergent to obtain a clear understanding.
Next, I did not like the angle Veronica took with Tris and Four's characters. She made Tris out to be weak. She was supposed to be at the top of her initiation class and was looked up to by other Dauntless members because of her actions in book one, but she was a total head case in this book. I really wanted Tris to pick up a gun and defend herself. She needed to stop feeling sorry for herself and wasting the life her parents sacrificed their lives to protect. Also, what sort of person would side with her boyfriend's abusive father behind his back? The lack of communication between Tris and Four was incomprehensible to me. They should have been a team, working together towards a common goal.
With regards to Four, Veronica really played up the "he is a coward because of his father" angle way too much. She made his character out to be very harsh and emotionless. He seemed to lack a sense of compassion, which I don't think fits with his character. I also didn't like how Veronica seemed to add a make out scene every so often just to keep their relationship together. There really wasn't a connection between Tris and Four the majority of the book. They were working independently and didn't share anything personal with one another until the very end.
I could bring up some additional issues with the book, but I will move onto the positives. The book was fast paced due to all of the action scenes, which were very well written. We also got to learn more about life in the other factions and how all of the factions and factionless interacted with one another. We can also see first hand that life for the factionless is not as bad as it was made out to be by the leaders. I feel like Veronica left the possibilities for book 3 wide open. I have no idea what direction she will take, but I can only hope that all of the drama between Four and Tris is over. They need to work together and Tris needs to toughen up again if she is going to be of any use in the final book. She needs to stop thinking about all of the things Four taught her during her initiation and start actually using what she was taught. She needs to be the strong divergent character who is not only Smart (Erudite) and Selfless (Abnegation), but Fearless (Dauntless) as well.