This episode is the turning point in Dukat's character arc. It explains why he becomes so unpleasant later: the dermal regenerator accidentally sealed the wrong hole.
What is love? Baby don't hurt me. Don't hurt me no more.
Is this a romance of the week episode? I think so. "But Ben," you say "these two characters were married in a past life so it's not really a romance of the week type scenario." To which I'd respond "My name is Godfrey, godsdamnit!" Structurally, it's a romance of the week episode. A love interest that we've never met arrives on the station, a main character falls in love with them (again), the love interest goes away leaving the main character heartbroken, and none of these events are ever mentioned again. The previous relationship between these two characters makes this a more believable love story than any of the others on the series, but it's still a romance of the week by my definition. And yes, I do mark the episode down because of that, and in this case it's a bigger problem than normal as I'm expected to believe that this is a love that spans multiple lifetimes yet Jadzia forgets about it next week. And within a month she'll be wanting to jump Worf's bone.
The writers sure have a thing about exile, don't they? Garak is exiled, Worf has been exiled twice, Odo is in self-imposed exile, Quark will be exiled before the season is out, and in this episode Jadzia is threatened with exile. Exile and the death penalty, Star Trek's go-to punishments when they need to generate false drama. Wasn't the taboo against reassociation enough of a punishment? Wouldn't the episode have been a more appropriate allegory about homosexuality without the exile thing? Your average, everyday homophobe doesn't want to exile or execute homosexuals (at least not in western societies), they just want them to stop doing homosexual acts. And that taboo, that expectation of heterosexuality by friends and family, is bad enough that some homosexuals try to hide their true nature. And that's real tragedy right there. Wouldn't it have been more tragic if Lenara chose to leave because she couldn't live with the taboo rather than making a somewhat reasonable decision in order to protect the symbiont? Congratulations Star Trek, you managed to do a gay allegory where my sympathies lay with the conservative characters. That's quite an accomplishment.
Problems aside, this is definitely one of the better romance of the week episodes. I actually buy into the romance that's happening for once. And while the episode is centred around two women it doesn't feel sensationalist or weird, it just tells the story straight, Lenara could have been a man and the episode would have been exactly the same. Even the infamous kiss scene didn't titillate me, and a part of me is usually very sensitive to displays of lesbianism (I'm talking about my penis). So it's a nice love story overall, but it's not without its problems.