Summation: Tris and Four didn't have distinguished enough voices for the alternating POV thing to work. Half the time I would forget who was the "I," if I left the book to go do something for five minutes or more in the middle of a chapter.
Also, all I thought the whole time was "THIS IS NOT HOW GENES WORK!" And it's not: http://reflectionofreality.com/post/98102281799/why-the-premise-in-allegiant-doesnt-make-sense
When you write something, particularly a thing with religious-y undertones, getting basic facts about science correct would be great.
Overall I liked this book :D It's not better than Divergent, but in my opinnion, it's better than Insurgent. :D I like the dual point of view, but sometimes t felt like it's the same person... But, I read the book while listening to an audiobook, so I didn't have a big problem with the dual point of view. :D