Discussions should be about taking off the gloves and giving each other a hard time to force each other to rethink our positions.
About DS9, I think that the perception of the series is interesting. Of course there is the majority who views it as slightly inferior to TNG but there are also people who absolutely love it and want Trek to be totally serialized again and there are folks who hate it because it is too grim or too tedious. One could on the one hand argue that it is better for a piece of art to be loved and hated than to be perceived as mediocre by everybody but one could also argue that it is not a coincidence that TOS and TNG are the most popular series.
Of course appeal to popularity is a slippery slope and subjectively I totally disagree with this majority opinion as TOS just features too many bad episodes for my taste but I also gotta admit that there is something powerful in the very setup of the show. Like TNG it is timeless and not a story which ends when Sisko goes home to the prophets, Janeway goes home to Earth or Archer, speaking hypothetically, defeats the Rommies and sets up the Federation. It can go on and on and on like a short story collection.
But then again I think in the next moment about a Trek "novel", another DS9 that runs for a season or longer.
So yeah, somehow I think that this question is the most basic one.