It's good!
This is the first I've read by the author. I will shortly be reading the rest.
In many ways, standard science fiction. Space ships. Aliens. Interspecies culture clashes and translations.
On the other hand, this is first and foremost a character novel.
Unlike much sci-fi that numbs you to the parade of unpronounceable names and words, Chambers walks you through an intimate connection with Rosemary, Ashby, Kizzy, Sissix, Ohan, Corbin, Jenks, Dr. Chef, and even Lovey the A.I. A few brief characters like Nib and Bear stick for a time too.
I appreciated the soft inclusion of standard sci-fi mechanisms without explanation or justification. For example, we've all read books bending over backwards to justify some version of the ansible for instantaneous long-range communication, but Chambers expertly includes it for an appropriate conversation, using the common name, and moves on.
I detected only one salient-to-me-from-the-2025-perspective potential sci-fi "error": The claim that you, or a species in general, cannot create an A.I. smarter than yourself. I won't find the page to quote it now, but it said something about not being able to program the computer to do something that you don't know how to do yourself. This was not central to any plot thread, other than to emphasize that one species capable of impressive mathematics in their head refused to teach their techniques to computers. It sounded strange to hear that kind of assertion from a sci-fi book, after hearing so many similarly sorry arguments for the supposed limitations of any model that (gasp!) merely trains on data and makes predictions like, e.g., (faint!) an LLM. But this book published over 10 years ago, and it does wonderful justice to some considerations of A.I. "sapience" (which may have been further complicated if the intelligence of the A.I. was emphasized to astronomical levels like in in Ian M. Banks' Culture series), so I give the whole thing a pass. I'd still find some way to drop at least that half of that clause in that sentence... Maybe simply suggest that no A.I. had yet replicated the Sianat Pair's techniques. That wouldn't have given me a moment's pause.
Philosophical, ethical, cultural topics contemplated by the characters and plot include sex (monogamy, polygamy, interspecies, taboos, grey areas), violence (war, self-defense, infringement of personal safety, clashing civilizations), friendship, kinship, various forms of family, belonging, deception, trust, personal and international economics, ... basically everything!
Usually the tech and the philosophy are my main draw to sci-fi. The characters are a means to explore the world. Chambers' book bucks that trend a bit, and I like it! Believe me, I'll finish the second half of Inversions soon and complete the all-tech-and-philosophy Culture series (maybe that's too rough, there's plenty of character there too, of course), but I may sneak a Wayfarer entry in every other.