Wow! This is a fantastic, clever, wonderful scifi book. I loved the explicitly humanoid species (that are probably expanded on, especially their origin, in other parts of the series). I loved the mostly-androgynous species, their peculiarities, the mechanics of it all, the implications. I loved the protagonist and the carefully spun story arch - but I loved most that the narrator/protagonist was both clever, relatable, and fallible - there were several instances where, in the middle of narration, you started to think "Hold up, I'm sure that's not quite …" or "Isn't that just your weird bisexual bias …?"