I LOVE this episode. An underrated gem. Things to note:
1. The introduction of the Cardassians. Who knew that this species would become a key element to much of the Star Trek saga, which of course led to the introduction of the Bajorans, and the rest is history. I found it refreshing to meet a species that was not yet another "huge" threat to the Federation, but was a thorn in its side nonetheless. It just makes the Star Trek universe seem more realistically diverse. Let's face it, they seemed somewhat technologically inferior, seeing as how a lone virtually defenseless Nebula-class starship was kicking Galor-class ass left, right, and center. Plus, you have Mark Alaimo as a proto-Gul Dukat, one of the finest Trek villains EVER.
2. Finally a great character episode for Miles O'Brien, plus some nice Keiko moments. It's great seeing indepth scenes with married couples together on the Enterprise. There's supposed to be all these families onboard, but we never got to see enough of that.
3. The episode is a thoughtful commentary on what war can do to people, even a decorated, veteran starship captain. The touching "Minstrel Boy" scene is a classic. You can imagine Captain Maxwell as having once been a heroic figure like Kirk or Picard, but for whom things just went REALLY badly: "I'm not going to win this one, am I chief?" "No, sir".
4. Picard vs. Gul Macet. I loved the political intrigue, something that up till now had been lacking somewhat in TNG.
"Take this message to your leaders, Gul Macet...we'll be watching."