Romance for adults. How have I never read a romance about two people finding love late in life before? And it's sci-fi! The stakes are high, the tech is creative (hello, artificial wombs with babies floating around that need looking after), and the cultures feel real enough to facilitate the conflict of ideals between leads. The politics also come across clever without taking up so much space as to be boring. 

What glows about this book is how it is so enjoyable despite featuring two mature, intelligent, measured characters. After a bit of a tumultuous forced-proximity start, it turns out they are both as  reasonable and generous as two people on opposite sides of an armed conflict can be. It's not a will-they-won't-they, it's a will-the-world-let-them-won't-it. There are moments of high drama, but also moments of day-to-day life. It makes the usual formula of pining and misunderstandings feel juvenile. Despite being set in the stars, this couple feels like they could be your aunt and uncle. Aspirational in a very comforting way.