Thanks for that, Sumana; I'd not consciously thought about Ancillaryverse as such a conversation with so many other classic parts of SF, so thanks for flagging that up! I picked it up without really realising it, so lightbulb moment ensued.

Part of what put AS over AJ for me was that I have a very hard time with narratives that indicate up front that Terrible Things Will Happen, then build up to those terrible things in flashback or split narrative (I'm reminded of Gus Van Sant's film Elephant, which gave me a migraine). But also...I feel like the Ancillaryverse is the story of how the Radchaai system is actually completely failing its tenets (Justice, Prosperity, & Benefit), and while AJ is the story of Breq learning to understand and parse that some privileged individuals are being failed, AS opens up her understanding, and the hunch the reader must have, that the whole system is actually systemically broken.

I like that Breq is unreliable in a way that is clear to Me The Reader, also...I have a hard time with unreliable narrators that I want to take at their word.

More on this hopefully--thanks for the doc rec as well, as for some reason I'd not heard about it. Totally sounds like it would be my thing.