Of course this was a good book. A very good book, in fact. I thought the author did an amazing job capturing the voices from the point of view of each of the characters. The weakest, to me, however, was the voice of August himself.
In any writing, I don't like my protagonist to be all good, and my antagonist to be all bad. The world doesn't work that way, and writing that reflects that doesn't feel honest to me. But for Middle Grade or Juvenile fiction, I think it is even more important to not have such a black and white world. I would have liked to have heard Julian's story, too. Knowing his motive would still have kept him the antagonist but it might help to show why he was lacking empathy.
Via, the sister's, voice was the strongest. Her story was also the most heartbreakingly honest.