New poster, but owner of a new UN55D8000. Since January, this is my 5th Samsung set, of various denominations. For contrast sake, I'll go over some of them.
1. UN55C630 = Very nice picture. Lacked apps. Dark areas of screen were too dark, eliminating shadow details. Sound not too bad.
2. UN55C6300 = Had brighter details due to LED, but terrible flashlighting. Also, two horizontal bands across the set which showed in both dark and light scenes. Despite being brighter, was not as dramatic a picture. Sound not as good as first set.
3. UN55D6000 = Brand new set. Bad pixels. Didn't evaluate it as it went right back.
4. UN55D6000 = Brand new set. Display pretty uniform re: flashlighting. Picture cloudy; not as sharp as last years sets. I think they may have changed the panel, as it seems less reflective, but also conveys less depth. This unit must have had something wrong with the firmware/software, as it had real problems displaying colors in a uniform fashion. Viewing angle significantly worse than 1-3.
5. UN55D6000 (set 3) = VERY uniform panel. So far no dead pixels. Better viewing angle than set #4. Very uniform re: lighting. Samsung must have cut back on the motion processing. No matter what settings I use, I cannot get that "soap opera" look that sets 1 and 2 had. Contrast level and brightness pretty good. Colors are not so hot. Either oversaturated or washed out. Already had a software update the same day I brought it home...
These are just my impressions gained in my quest for the perfect (reasonably priced) set. After the 4th Samsung (or maybe it was more) I nearly traded it for a Sharp. Honestly, IMHO, it's a nice set if you get a good panel. I'm a bit concerned about the set being released to the public in March, and already needing a software upgrade. I'm also disappointed that it's not as clear as the MUCH cheaper UN55C630. I did promise the wife though that I was done playing with TV sets, so I guess I'm stuck with it.
I think my picture is on the "do not sell to this man" list at BB Orlando. The two stores I went to were very accommodating (Thanks Chris and Ted!). BTW, my wife thinks all the sets were fine (except the one with the dead pixels), so your mileage may vary.