At least as efficient as Nadochi with my stubble (probably more so), but I could see that being reversed for someone with less coarse hair if my hunch on flex is correct. I really like the Diamondback a lot. It is along with a few others at the top of my heap. . . .where mood says which one I like better.
The Nodachi is not in this group. It isn't that it's a bad razor, the safety bar on the Nadochi feels crisp to me and the safety bar on the Diamandback has a duller feel. I guess I like the dull feel rather than crisp, perceiving the dullness as smoothness. I also think the dullness of the Diamondback safety bar lets me fine tune the shave with pressure, like the steering on a '70s Cadilac. The crispness of the Nadochi safety bar has more of a spirts car responsiveness to pressure that I don't like. It is almost like the comparison to iKon Standard (dull) vs iKon Tech (crisp).