Just finished it. One point I want to comment on is the little bit of dramatic irony with the Cardassian labor camp's second-in-command, Trina, being disturbed by the illegal research going on in the secret base, and wondering if the whole thing was actually some illegal conspiracy that he should stand up to, and deciding he'd worry about it later. It kind of feels like he's being set up to side with the Bajorans or help them in some way. Except he ends up doing nothing of the kind, our next major encounter with him being halfway across the book where he gets stunned in a gunfight then shot execution-style. It's the kind of thing that makes you think, and reinforces one of the recurring themes on the Bajor-side of the novel with Kira, especially, where it doesn't matter how you feel or what you say if you don't do the right thing (Kira actually had a line to that effect in the show).
Especially with the thread having a big discussion on Dayton's tendency towards big solid potato-y chunks of exposition when building on prior stories, I wanted to call out that subtle, almost impressionistic little bit of storytelling that lets the reader do the work. He did something similar at the end of, IIRC, "Hearts & Minds," which was my favorite part of the book.
(Another comment I wanted to make was that before the Enterprise got the distress call and left to check it out, I was thinking it'd be a great time for a saucer separation so half the ship could keep doing relief efforts once that inevitably happened, but such was not to be the case.)
Overall, I really liked this "lost backdoor pilot of DS9" concept. And with the way it backfilled more modern continuity with the California-class ship and Dr. Crusher's first meeting with Dr. Tropp, it feels like it's of a part with the expansive litverse and just makes the whole Trek setting feel more cohesive.