Would you prefer to see a mix of traditional mattes paintings with CGI, or all-cgi ones like Enterprise was. It occurred to me after looking at the latest matte from TOS-R that some of the good quality mattes in STNG could also be redone in 3D fashion. There really would be no edict that they would have to make them look like FX of the day. A CGI matte would not be too far off.
I say leave TNG alone. It's good enough as it is, we had the effects to make the show good. For TOS it was understandable, because even though effects were ok for its time, it still wasn't the same as we have now.
Maybe for the latter seasons of the show, but you can't seriously say that Seasons 1-2 of TNG had anything like decent FX. But then, the FX weren't the only thing shaky about those early episodes... the spandex uniforms and the overly loud synth soundtrack didn't help matters much... Once you get later on, with better FX, the uniform upgrade and more reliance an actual orchestral soundtrack, things improved greatly...
Of course, remastering would only address a few of those 'dated' aspects of the show, but, given how fuzzy and aged I've noticed the syndicated episodes looking on my non-HD cable outlet, it would appear that Remastered TOS totally spanks TNG in the visual department. Personally, I wouldn't mind an FX overhaul, especially for everything before and inclusive of 'The Best of Both Worlds', but even a simple, really thorough digital cleanup on par with what the TOS master tapes got for their remastering would be greatly appreciated...