Insurgent still has the ideas, characters and setting of Divergent yet I found that it felt far weaker. That is not saying that it was written any worse but rather that I felt it went off on a less interesting and satisfying direction than was suggested at in Divergent. I find that Veronica Roth is a talented storyteller with interesting ideas and her writing is workmanlike rather than full of literary flourish. Which makes it good writing in my opinion as it achieves its aims by conveying the story as intended. Yet what let me down was the fact that it felt perhaps like many things continued to happen in a similar fashion to Divergent rather than expanding upon that base and creating a larger scope and vision of the world hinted at.
Perhaps I was hoping that Insurgent would focus on a sort of revolutionary movement. And to some degree it does. It focuses upon the aftermath of Divergent and features some of the other factions not focused upon in the first novel. Yet I felt that Divergent's sequel would lead into a larger, warlike revolution whereas it felt that Insurgent became a story about deceit, uncovering the truth and fighting one small battle for control of some information. Perhaps I merely felt like the plot let me down in that it was not as grand as I hoped. Or perhaps it felt more like a gap filler to me. Either way I did not enjoy it as much as the first.
That said anyone who liked Divergent should read this and see whether or not they like the direction of the series. Its solid enough to be likeable and so deserves 2 and a half stars but it's not remarkable enough to remain fixed in my memory when there are many other strong books to read.