I'm a huge DS9 fan and was looking forward to this episode as a highlight of the season...and it's just...okay.
Yeah, I'm not immune to fanservice. It was nice to see DS9 again, and hear the theme. It was nice they got Nana Visitor back as Kira, and Armin Shimmerman back as Quark (though he sounded really off - I couldn't tell it was him until the end of the episode.
But...this was all they had? Really? There was really not much story to be had here, and most of the crew was off doing things which didn't have much to do with DS9 at all.
Mariner - who logically should have been a big part of the plot, since we know she was stationed here in the past is hived off in a subplot on the ship dealing with her relationship with Jennifer until the last few minutes of the episode. I was happy the season finally recognized their relationship existed again, but the silly subplot here could have been in literally any episode. Most frustratingly, the end of the episode makes reference to her bar tab at Quarks (and past with him) which would have been a much more interesting thing to do with her character this week.
The stuff with Tendi/Rutherford and the tryhard adopted Orion was arguably relevant to DS9 this week, but really it could have easily fit into any other episode and worked just as well. Worse, it doesn't tell us anything new about Tendi, since we already knew that Tendi had a background from a pirate family. For awhile we get to vicariously feel her annoyance with the dude, but...that's not really a character arc. Everything is far too on the nose.
I give the episode some points for the banter between Quark and Kira near the end feeling like DS9, but...there was so much more they could have done. Why no gag with self-sealing stem bolts? Why not show the fat Klingon restaurateur? Why not have the lower-deckers mixed up with a second-stringer who would feasibly be working with them, like Rom or Vic Fontaine? Maybe my expectations were just too high, but there were so many missed opportunities here with the first canon re-introduction of DS9.