It's odd, to me at least, that so many folks seem to be unhappy or have had issues with their 65X850B's. I say again, I am massively happy with mine. The blacks are impressively black, even for the lighting system it uses. I don't have bleed, I don't have flashlighting, except in the case of only two of the test colors I have used, and even then it's not even that, i would qualify it more as mild inconsistency. Maybe I got super lucky, I hope that's not the case, I genuinely do. I am a die hard Sony addict. The one thing it seems that is becoming more true is the term "panel lottery". I think that is terribly unfortunate.
The blacks on my TV are really quite black, with some very limited exceptions. I don't have the artifacts so often associated with frame dimming. I'm not sure what to say. If someone wants to share with me, either in thread or by PM, how to get into the service menu, I will share my panel info. Hopefully this might add, in some way, to the discussion. Bottom line though, again, I am really very happy with my x850b. I am not going to suggest that i would not prefer to have a X950B, but I had the money I had to spend, so I did. As such, I recommend the 65X850B.