A:Answer I'm glad you posted that...the X830C is a TERRIBLE set because it has laughable contrast, and I've been unable to find out ANYTHING about the X800C. So do dark scenes on your X800C lack contrast, even if you play with the settings, like 'vivid', contrast, etc.? If so then it sounds like it might use the same panel as the X830C, in which case I'm avoiding it :-/
It's crazy, I'm probably going to buy a 1080p set just because I can't find a single 4K set that actually fits my needs...