Just wanted to add that this hone is now half of my magical combo.
I hone a razor on 1K / 4K until it passes the TNT, and perhaps 2 pyramids to see if it'll mow down arm hairs.
Then I do 100 passes on this narutaki stone with slurry, and then 100 passes on the nakayama with slurry.
This combination seems to do the trick every time on razors with known good steel.
It has progressed to the point where I am considering selling my big 8*3 coticule.
Then again, it might come in handy sometime.