Here's my settings:
contrast: 50 (default I think)
brightness: 60
Standard View mode
Low input lag: on (default)
Black Stabilization: 50 offers the best compromise which is handy 'cos it's the default. 40 gives better gradient contrast on the upper range but not as good black levels. 60 gives very good black levels but 1/4 of the blue gradient is washed out. It also depends on viewing angles.
Advanced Contrast: 0 (default)
Blue Light Filter: 0 (default)
Response Time: Normal or Advanced (massive ghosting on text movement with Ultra Fast).
Color Temperature: User Color
Red: 91
Green: 90
Blue: 100
OSD Timeout: 30 (!!)
RampageX: Off
I had to study a range of "skin tones" to calibrate it by eye.
Issues I've had:
No ULMB mode or too many artifacts on the integrated pixel response time feature @ "Ultra Fast).
Couldn't get smooth contrast on all spectrums (the upper end of purple was the problematic one). Scratch that, it's ok with my current settings.
The backlight appears to 'bulge' in several spots at the very edges of the screen, as depicted below. It's really only visible if you're sitting close at a certain angle. Could be related to the curve of the monitor.