The storyline was trash. Especially the third book's story. I dropped it half way through the book because it was such a departure from what became before it with the factions and all that. I ended up reading what happened in summary at the end. It wasn't a good ending.
Why would you guys expect the third book to deal with factions? The entire purpose of the story is to breakdown the concept of factions and one size fits all aptitude tests. In the second movie (I've only watched the movies), Tris' brother says that the message was designed for a Divergent to decode when we're close to a factionless world. You guys didn't realize that by the end of the second story that all the factions had cast their differences aside to help each other?
It was even more glaring when Tris tells her brother that their parents would be ashamed of him and he replies, "Well I've sacrificed you, my own sister, to keep order and save all of our people. What's more selfless than that?" I was like this muhfukka is still trapped in the matrix. He doesn't realize that his sister is trying to show him that as a human he has a complex personality - one that requires him to embrace the other 4 facets of his character.
Once you break down "the wall" - symbolism here - it's time to explore the why's and what's that lead you to creating a personal prison.
I just thought it was obvious as this is the take home message in all of these stories dating back to the Lord of the Flies.