Bratlie, the greycast denim fades 3 times faster so if you still haven't seen progressions on your greycast i wouldn't recommend buying a dry black. ;)
my SJDB is 98% cotton and 2% elastane, and i've been wearing them for about 3 and a half months consistently now. as an owner of a somewhat broken in RRDG, i can attest to you that these are discouraging. i may post pictures up sometime soon but they will look as if they've only been worn a week.