My "base" blade for comparison are Feather blades, and I find Kai in Superslant L1 and L1++OC more efficient than Feathers. Actually of the razors I have Kai work the best in my SuperSlants. But of course YMMW as it is with such things. Regarding sharpness interestingly my perception of Kai blade sharpness does not put them on the same level as Feathers. Seems that larger blade exposure and perhaps a more rigid blade seems to up the cutting ability a bit more than sharpness does it for the Feathers.