Winn: You live without a soul, Commander. You and your Federation exist in a universe of darkness, and you would drag us in there with you. But we will not go!
In addition to memorable performances by Kira/Visitor and Marritza/Yulin, I think this episode was also a turning point for Kira's views about Cardassians.
Before this episode, she saw them all as "the enemy". After this episode, she saw them as more nuanced, with some of them honorable.