I agree with you on the replacements, they have all been bland. I would say, DS9 seems to have had more of them and less investment in them all at the same time than a series like TNG of VOY has. I personally love Ezri and the Aventine. I also don't want Sisko to be done with the Prophets and Bajor. Honestly the DS9 series was once my favorite, but it's just not anymore and I think it's because they lost so much of the crew that the place has stopped feeling like the series and what I loved.
It's really around the time of the 'worlds of' books that thing started going awry. By the time of the jump forward, the resemblance between where We Were when the series ended and what we are reading now got significantly less. Ezri and Bashir split (pointlessly and to my own and others distaste I suspect) Sisko goes through some stuff that essentially negates the character...less fun.