It's a quirk of mine that I find it difficult to read fiction for fun by daylight; I get distracted too easily, and can't really concentrate enough to make real progress. So I end up doing almost all my reading at night, which means that good books invariably make me stay up late reading. Rosemary Kirstein's The Lost Steersman kept me up late, all right -- but it also made me resume obsessively reading the next morning, locking myself in the bedroom away from all distractions until I'd finished it straight through.
I've been somewhat circumspect when reviewing the previous books in this series, because I'm wary of being too enthusiastic about books I like -- people who read my reviews and go into the books with high expectations are more likely to be disappointed than those who come to them without such expectations. I'm especially wary of overpraise when a book is hitting all my soft spots (as Kirstein's books do), because a book that I love idiosyncratically is even more likely to disappoint others.
But The Lost Steersman is so damn good, in ways that I expect to be widely acknowledged, that I don't see much point being coy about it. Bluntly, this is a spectacular work of science fiction, and ranks right up there with A Deepness in the Sky and The Sparrow as a modern classic of the genre. As good as Kirstein's first two books were (and I loved them), this one's even better.
Beyond that, I have little to say. I'm not going to talk about the plot at all, because to do so would be inevitably spoilerish, both for this book and its two predecessors. I'm not going to try to highlight particular strengths of the book, because it's all good -- the world-building is first-rate, the characters are great, the pacing is brilliant, and the plotting is suspenseful.
And now that I've jacked your expectations far too high, ensuring your eventual disappointment, go out and buy The Steerswoman's Road and The Lost Steersman. Feel free to complain later about how you would really have liked them if I hadn't talked them up so much; because at this point, I don't even care if you like the books -- I just want enough people to buy them so that I can be certain the sequel will be published in a timely fashion. If I have to risk your enjoyment to ensure my own, that's a risk I'm prepared to take.