This episode basically follows the same formula as the Next Generation episode "Disaster". While in the Gamma Quadrant on a diplomatic/commercial mission, the Defiant encounters some Jem'Hadar ships which cripple the ship. The crew is split up into small groups as a result and the meat of the episode lies in how they interact to solve the crisis.
I really enjoyed Kira's attempt to keep the barely conscious Sisko awake; the realization that their relationship, while close and friendly, essentially revolves around work, was an important one. Nana Visitor did a really good job. I liked how this story resolved in the last few minutes of the episode.
I also thought Jadzia and Bashir's plot was good too. By this point, their relationship had pretty much settled into close friendship, but after this incident it's obvious that Bashir still cares for her deeply, that she knows about it, and that she doesn't necessarily mind it.
The plots with Worf and Quark were OK. I suppose it's necessary for Worf's development to see him struggle with commanding other officers, but it's not that interesting to watch. Quark's plot (with James Cromwell's character) is pretty generic, though as always Armin Shimerman does a good job of keeping us entertained.