Ira Steven Behr always wanted to do a Trek version of Brigadoon, and got a nasty lesson in being careful what you wish for. The DS9 Rewatch hits a low point with "Meridian."
Ultimately, as with every romance-in-an-hour episode, it’s on the back of the guest actor to make it work, and Bret Cullen doesn’t pull it off. His sodden attempts at chemistry with Terry Farrell fall completely flat (tellingly, there’s more emotional depth to Dax’s single-scene talks with Bashir and later Sisko than in any single moment between Dax and Deral). His reversal in deciding to remain on Meridian is unconvincing (any society so reliant on one person is going to fail, even if they get thirty years instead of twelve days next time), and the willingness of either Deral or Dax to uproot their lives (and in the latter’s case, her very state of being) for each other is never at any point even a little bit convincing. The script tries to insist that Dax has thought it through, but Sisko’s concern that she’s buggering off to spend sixty years as a light blob with someone she’s known for a week is never properly addressed.