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.
This is an excellent DS9 episode and is one of the best hours in the franchise. Excellent performances by Nana Visitor and guest star Harris Yulin as Aamin Marritza.