Interestingbas I have just bought a Kuro Kage 65 to trial. How stiff does it play Jezz?
Given that I have always played a regular shaft in my driver and that I'm not getting any younger (50 approaching alarmingly rapidly), I would say not that stiff. That was my concern, that the stiff shaft would leave me hitting everything low and right when the timing was out, but thus far, not so!
Maybe the tweaking of the head to 11.5 just helps counter that, but I don't balloon it at that loft, which would have been my concern with going to 11.5
Still waiting for it to really fail me, but I'm sure my fragile swing will eventually find a way to make it not work!