This was my favorite of all the Armored Space Marines genre. It goes deeply into the psyche of the characters, so that they become very real people. The abrupt shift in perspective in the middle of the book to what seems to be a completely different protagonist originally threw me, but it makes the story SO much better! It's definitely for mature readers only. These are NOT the kind of people you want your kids hanging around with, and the deep dive into the motivational factors is what makes the characters so real.