Watching the fifth season on blu, the softer look is actually growing on me this time. It never looked that great in SD, as it made it appear more video like than anything else. I remember being fooled into thinking they might have switched to shooting with video because of that. Now with the season in HD and in more vibrant colors, I'm fine with the use of soft filters.
If/when DS9 gets the HD treatment, we should definitely expect the soft look being much more prominent on that show than it ever was on TNG. I always thought that show is more suitable with that soft look than TNG anyway. I don't think VOY had that much soft filter, but an HD treatment of that might say otherwise. I think ENT definitely did, so much that many thought the live action footage on blu was just upconverted like the f/x.