I've made this complaint before when other review threads reached this episode and some found it to be a bit odd, so I'm throwing it out there again for the sake of discussion. I don't like the use of the Defiant in this episode. Here's a new starship that's supposed to be unlike anything we've seen before and they use it as a glorified runabout. I can understand wanting to use the show's major new setpiece, and justify the cost of the ship's model and sets, but using the ship in this way makes it feel less special. It's not helped by how limited the use of castmembers is. Sisko, Jadzia, and Bashir are the only ones to go to the Trill homeworld, the other characters remain on the station, so there's no reason from the point of view of the plot why they couldn't have gone in a runabout, especially since they were going there as a precaution and didn't need to travel at warp 9.99993.
That's not a big enough problem that the episode loses points, it's just something that adds to the awkwardness of the episode as a whole. As I said, only three main characters go to the Trill homeworld so the dynamic feels off. If there had been a b-story back on the station about Odo learning to cook while Kira silently judged him then things might have been better, but as it is the pacing doesn't feel quite right. Two or three characters walk from one room to another slowly filling time until the mystery's big reveal, which isn't all that interesting considering what little reason I've been given to care about Trill society. As I said previously, as a species the Trill are kinda boring and rely on a single gimmick, so I can't say that I care whether or not 50% of them are eligible for the joining process.
All that being said, the character stuff for Jadzia is good enough, and making one of Dax's former hosts a murderer is an interesting direction to go in, not that it means much for the character in the long run. We get to see where the Trill symbionts live which is neat, even though it does once again raise the question as to why someone would even think of sticking something from a pond of goo into their stomach. The Trill interpretation of IDIC sure was extreme.
Also, processors in the future must not have been able to keep up with the shear scale of the galactic digital library system because Shazam took days to figure out what Joran's song was. Or perhaps the Federation's internet was on strike due to new piracy legislation the council was considering. Who knows?