In Canon log I found that when exposed for highlights, setting middle grey to 32 IRE, you get beautiful highlight roll off, but detail in the darks is sacrificed, especially color information. I did a test when a subject with dark brown hair. When I exposed at 32 IRE her hair was black, when I raised middle grey to 40 IRE then 50 IRE her hair moved to dark brown. From my findings, if you would like to preserve saturation detail in the darks effectively, you need to overexpose middle grey by about two stops from where canon recommends it, as long as your highlights don't clip. You can download the original prores 422 here from the test here. When I normalized the different clips I adjusted luminance and saturation until vector scopes and waveforms were relatively overlapped. Have you guys seen these results too?
http://www.mediafire.com/download.php?1b3z5q11vadna1u
http://www.mediafire.com/download.php?1b3z5q11vadna1u