60hz refresh is the native refresh.
Only use the standard mode with Advanced DV mode on. This will give the most accurate colors (I found out quickly about the banding that happened when you select other modes)
Use the default sharpness which should be 16.6.
Contrast should always be @ 50%
Brightness seems good to me @ 50% during the day and 30% during evening.
For RGB I use:
R:96.4
G:98.8
B:95.6
That's as close to 6500k as I can get it with my eyes, a sheet or paper, and a light bulb
I've had this since its US launch -- I hope you enjoy it as much as I have