Got my C20M in today, while HPG is trying to figure out the voodoo of the cubic inch, I figured I'd post some comparison shots with some "known quantities."
The Bags (Left to Right) are: Kifaru Scout - Tarahumara - C20M - Kifaru Zulu (G1, the it is not fully stuffed out into the collar)
Hope these might be a bit of help to those who are looking.
The C20M is a nice bag, light weight compared to any 1000d bag I've seen. Just gotta wait until mid March for my EMR to show up.