I have owned the UN55D6000FXZC for about a week now. It is a H301 Panel . I do not have the flashlighting in the corners...yet
. However the display model - same size - that they had in Future Shop had serious corner flashlighting.
I posted my settings on the Samsung un55d6000 settings forum. My backlighting is at 13 and while I commented that I was having some clouding when the TV is black I did not notice it while I watching any movies or TV shows. The off angle viewing seems to be on par with our older 52" Samsung, an A 550 with the S panel.
I am not sure how well I did with the calibration, but I feel that the picture does look better than when I purchased the TV.
I have 30 days to decide on this panel and I think I will be using most of that time to assess my options. At the same time, hopefully there will be a few more reviews and comments on the TV on this forum that will help me make my final decision.
As a final comment it does not seem that this panel has the serious issues described in the forum on the 2010 models, but as I said I have only had it for a week.