Eh, I liked Deep Space Nine personally.
It was refreshing to see a Star Trek show that actually knocked the Federation off it's pedestal, and showed humanity in a not so great light from time to time.
I enjoyed Deep Space 9, but Star Trek's idealism is a pretty massive part of why I love it so much, and it's not like there's an over-abundance of optimistic science fiction on television these days. I actually can't think of, well, any.
For me, a return to TNG's idealism would be the refreshing thing, since it's been so long since properly optimistic sci-fi was last done well. The closest television's gotten to that sort of thing since TNG is probably Stargate: SG-1/Atlantis, and it's been quite a while since even that was on the air.
I'm hoping Bryan Fuller's show delivers, though my irrational - or, well, perfectly rational from my perspective; not so much from a more reasonable one - hatred for the reboot-verse, and the potential for it to be set there, has me worried.
Regardless, going all the way back to DS9: I actually thought the series did a decent enough job of showing the value of the Federation's idealism even as it challenged it in ways it hadn't been before, so I still like it. It's probably my second favourite Star Trek series, since I've never been a massive TOS guy. I might still prefer Babylon 5, though.