Had my 65 850B for 2 weeks now, replaced a 55 XBR8 with a dying FBU board. Started adjustments in Custom mode and settings suggested earlier in this thread. It looked ok and I spent a lot of time with a Blu-Ray experimenting to get my blacks to an acceptable level. I changed to the Cinema 1 and made a few adjustment to backlight and picture and a few others as detailed on page 26 of this thread and it looks much better. Very happy with the color and blacks....it will be staying on those settings for a long time.
I do notice some clouding in the upper right corner, flashlighting....call it what you will, when the screen goes black when transitioning to Netflix for instance, but I do not notice it when an image or picture is on the screen. The XBR8 did the same thing so I think this is fairly normal......don't want to play the panel lottery at this point but I will keep an eye on it.