Usually when it's the author who has provided a review copy rather than the publisher, I provide a caveat about how the author is a friend of mine or something of that nature, but this is the reverse: while she, not the publisher, is the one who provided it, I don't really know Kameron. She's friends with some of my friends, and I have entirely good impressions of her, but we don't actually know each other at all well. I tell you this so that you know it is not happy memories of late nights at convention parties or quiet afternoons sneaking off for tea just the two of us influencing my opinion here, since we haven't had any of those: this trilogy started good and has only gotten better.
Sometimes it's hard to review series, because of the problem of spoiler for earlier volumes and so on. And honestly, part of what makes Rapture so much better than the average book is how much it ramifies. The very best idea is to go back and get God's War, if you haven't, and start from the beginning and read them all. It will be very much worth your time. But! If you were thinking, oh well, God's War, I read it, I know about how good the series will be. No! You are wrong! It is so much better than that. Characters grow and change and get very weary and have bad decisions bite them in the butt. And also have bugs bite them in the butt. And various other places. My main caveat for this series is that it is not for those who are deeply squeamish about the insect world. But, for example, the set-up in God's War with the vast majority of the boys and men in this particular future being off to war for a lengthy period, if you read that and thought, hmm, I wonder if that's a steady-state solution or if it's going somewhere: going somewhere. And going somewhere really quite interesting and worth your time. This has always been a world with multiple cultures, but if you're a person who's annoyed when each culture seems to be a monolith that never gets affected by the others, you'll cheer when you see how things have started to shift even over the course of the trilogy as different areas on this planet have been exposed to others and changed accordingly. Or at least I did.
I am not a person who always ends up with a Favorite Character; that's not how I read, it's not how I have to read, and when people say, "I didn't really like this book because I didn't have a favorite," I tend to stare at them like they have sprouted a second head. But I love Inaya, and her trials with saffron and backstabbing. I also love that there is a vibe of "Let's get the band back together in order to kill them horribly." (Not everyone is dead at the end of the book. But.)
There is so much desert. There are so many bugs. There are so many people having to live with their choices. There are aliens and walls and trust issues, and--seriously, this book. This is better than either of the other two. This is such a fitting end to this series. I can't wait to see what she does next.