I've had my 50pz950 for about 3 months, and overall it's pretty solid. I don't have any issues with black level, and all the other features and performance are pretty solid. My main concern (and what prompted me to search for a new tv) is the image brightness. I prefer a brighter image and usually have lights on while watching the tv. I have tried the calibrated settings on flatpanelshd, and like a previous poster, did not like the results, primarily how dark the image was. I can adjust the brightness, gamma, and black level, but it washes out the blacks and colors, so no good there either. I did end up buying a LG 55lv5500 (not a huge fan of 3D), but there was terrible flashlighting and clouding from the edge lit backlighting, and I am in the process of returning it. I may end up going for a full array with local dimming, like the new sony xbr-55hx929 or maybe the older LG 55le8500.
All that being said, the pz950 is awesome when watching bluray at night with minimal lighting, but that is not the norm for my viewing habits. Also, as an aside, I don't play any type of games on it, so no opinion from a gaming perspective. Once I get the new tv, i'll be posting my 50pz950 on the classifieds page here on this site.