Grayscale is good right out of the box and is similar in THX, Adobe RGB and Natural modes, with a little too much red and blue in the higher IREs. It calibrated fairly well (see graph), with Delta E under 3 for the 30-100 IRE range, just increasing to 4.1 at 20 IRE. The default gamma setting of 0 gave a good average gamma of 2.27, but setting it to 1 dropped the average to 2.17. These are the only two you’d likely need. There are extensive gamma adjustments available, but gamma is so consistent, most people won’t need to use them.
The Quick Cal of Dynamic reduces the green that’s apparent in whites, but each decrease in Green Gain causes a significant drop in lumen output and eventually starts looking too red with light grays.