Something I really loved about DS9 in the beginning is that sense of isolation... I mean, it had that right through to the end, but it always seemed more pronounced at the start. That these were Starfleet officers who were genuinely situated on "the final frontier", far away from reinforcements. Sisko and co always had to shoot from the hip a bit more because they couldn't always rely on the fleet to come and help out.
That raw, untamed frontier quality was, to me, a very definite plus for Deep Space Nine. It was perhaps the most loud and immediate feature that spoke to how different this Trek was going to be. DS9 was not going to be just another pretty and pristine romp aboard a starship. It was going to be grittier and a little bit down-and-dirty. TNG was a fine wine while DS9 was a tequilla shooter and some hardtack.