Overall, I enjoyed this book so much. The last few chapters definitely passed the "crying in Wendy's" test.
I had a few issues, of course. This volume is substantially longer than the first two books in the series. I know, that's because there were so many things to wrap up at the end, and it's common for the last book in a series to be longer than the others (Harry Potter, anyone?). But this book also seems to slow down in the middle, as if Condie was trying to decide if she could wrap things up in this book, or if she needed to expand to a fourth book.
My other main quibble with the book (and really, the series in general, but especially this book) is that a couple things weren't explained clearly enough: the process of "sorting", and the whole biology/genetics/virology mess with the Plague. I'm still not completely understanding the whole bit with the immunity to the original plague versus the immunity to the mutation, and how the mutation happened, etc. I'm sure it's not as complicated as it seems in my mind, but I feel the author could have done a better job explaining it.It did seem that the conversations about the Plague in the book were a bit too technical for the average reader (or at least this reader).
I still don't subscribe to the popular idea that the idea for this book was stolen from Lois Lowry's The Giver. As I said elsewhere, it's been a while since I read the first book in that series, and I never did read the rest of the series, so maybe there's more to it than I'm seeing.
So, a good ending to a good series, although with a few rough spots. I think my sister would have enjoyed the series, especially the romance between Cassia and Ky, and the emphasis on Cassia's loving family, but I think she would have had some of the same issues with understanding the science.