Terrific. Tchaikovsky strikes just the right balance between exploring grand ideas and characters’ personal motivations; between narrative that advances the plot and mind-expanding visual description. I loved how he uses his training in zoology to flesh out the details of Portia’s society - to play with and ultimately subvert the reader’s initial feelings of revulsion. By the final chapters, you may be surprised whom you find yourself rooting for.
My only nit about the book is its generic-sounding title and trite, cosmic cover art. In contrast to the book itself, both of these decisions - probably the publisher’s to make - seem utterly phoned-in. You know how the saying goes: don’t judge a book by its cover, but ruthlessly judge the cover itself.