So in real life, by the time space combat got up to a usable level, we'd have A Is
to run the ships, or be bioengineered to take 50g acceleration no problem, and that's no fun to read. So - because it makes things interesting - the Shaa conquer the known universe and then institute a draconian set of rules on every race they conquer, forcing them away from bioengineering, artificial intelligence, longevity research, and much more. Once Williams hooks you on this premise in the first chapter (as he very handily will) you're dropped into a drama of alternately ridiculous and tragic protagonists, usually a step or two ahead of their Peers in figuring out how to go from privileged positions handed to them by the Shaa (they had a thing about feudalism) to actually fighting over/running an empire. It's hard scifi, with self-aware melodrama, suspenseful and fun space battles, and high-stakes intrigue, mostly carried out by astoundingly inept officers and politicians. They have an excuse. They never thought there would ever be a two-sided war. Protagonist snarkiness abounds.