Bought my DP-UB820 offered by Crutchfield. Found a bit of a quirk in that if only one high-speed HDMI cable is used to connect to the receiver (Marantz SR7012 in my case) then 4K discs play fine but BlueRay discs encounter random pauses while playing (related to layer switching I think).
Excellent 4K imagery. Lots of adjustments available to tailor the picture. Plenty of ways to connect video or audio
Needs both HDMI ports used for best results