Hi, since you will use CalMAN, AVSHD don't have correct Grayscale patterns which matching the RGB triplets CalMAN's Engine is expecting, as you see to the picture below; it's grayscale RGB Triplets are not matching exact the levels the CalMAN's Engine expects for it's calculations. When you will use it to perform Grayscale calibration your gamma will be slight off to the mid/low-end range because AVSHD's Grayscale patterns are rounding fractional RGB codes down to the nearest integer. DVE disk is doing the exact same thing, so it's not 100% accurate for Grayscale with CalMAN also.
The difference you will have @ gamma calculations for:
5% Gray = -19.22% Luminance error
10% Gray = -9.23% Luminance error
15% Gray = -5.82% Luminance error
20% Gray = -4.10% Luminance error
25% Gray = 3.07% Luminance error
30% Gray = 2.39% Luminance error
35% Gray = 1.90 % Luminance error
40% Gray = 1.53 % Luminance error
You will not have these errors if you use a calibration disk that matches 100% the RGB triplets of CalMAN's Engine.
But except that, AVSHD is a tool that anyone must have to his tools for other things, like a lot of useful patterns that is including.
Also using AVSHD disk for Color Gamut calibration you have 2 options: 75% Color (which has 100% Saturation with 75% Luminance) or 100% Color (which has 100% Saturation with 100% Luminance)
There is no 75% Saturation with 75% Luminance Patterns in AVSHD disk, no ColorChecker SG, ColorChecker SG Fleshtones, ColorChecker Classic, Luminance runs etc...
If you need accurate patterns which matching the RGB targets CalMAN Engine is expecting (to calculate the dE properly) from you to display, see for a calibration disk which designed based to excact targets of CalMAN's color engine.
BTW, there issues with HCFR also, from the AVSHD Saturation Sweeps; using 75% Saturation with 100% Stimulus; the patterns are not matching the RGB Triplets of HCFR engine, they are slight different.
AVSHD 50% Red Saturation Pattern has RGB Triplet 190.95.95 but HCFR's Color Engine needs/calculates errors from RGB Triplet 191.96.96, it's 0.42 dE2000 error.
AVSHD 75% Magenta Saturation Pattern has RGB Triplet 203.100.203 but HCFR's Color Engine needs/calculates errors from RGB Triplet 202.99.202, it's 0.36 dE2000 error.