Grain == Detail, leave your DNR out of my TNG-HD :-P
I happily have the DNR settings on my TV set to off and I love the quality of the TNG-HD results thus far!
Have you ever scanned a newspaper or magazine cutting at too high a resolution, the sort of res that's usually fine for scanning photos, but that makes a really grainy and fuzzy mess of newspaper print?
That's what a lot of TNG HD looks like. To a layman, it looks like either much of the film stock is in poor condition, or it's been scanned at too high a resolution.
Quite a few episodes I've watched from season 2 (OK, it's season 2!) have so much grain and distortion on the red of the command uniforms (usually Picard's) that the image seems to be on the verge of breaking up. That's the best I can describe it. Sorry.
I seem to be in a position now where due to the excess grain, I'm getting so disgruntled at the picture quality of a lot of these episodes, that I'm almost preferring the upscaled DVDs at 720p.
Going on eBay lately, there are a lot of second hand TNG Blu-ray sets for sale, even season 5 which has only been out a few weeks. You don't shell out £45 for a Blu-ray set and then stick it on eBay a week later. My guess is a lot of people are less than impressed with the quality.