Chris,

I don't know the answers to your question I don't have an asagi and I didn't try the hone with it's own slurry as I don't have a diamond hone either. I only have one other no name very soft Japanese hone that will yield a slurry with ease.

The suita is very hard, it is slow to lap on the wet and dry. It creates a rich creamy clay slurry when it is being lapped. It's harder than a coticule for example, much harder.

If I rub the nagura stone on the hone, not a lot happens. Eventually, the nagura yields a slurry onto the hone and not vice versa. All this tells me is that both stone are very flat and the nagura is softer, which it is. I can make an indentation in my rubbing stone with my thumb, but I could sharpen my nails on the hone and can not dent it. Do you know, sharpening your nails on a hone is a pretty good indicator of grit size as you can feel how smooth the hone leaves the edge of your nail.

If the suita was not flat, you couldn't use it. You can see a little blackness in the water from the swarf as you hone and so you know it is working. It hones the edge very slowly. The hone tends to jerkiness if you press to hard and so you do have to hone lightly. You can feel the hone doing its work and you can tell when you reach the optimum point quite easily.

Don't know what else to say really, except that it works and it really surprised me. Pleasantly.

I very nearly gave up on this hone because I expect a hone to have a range with and without slurry, harder v's softer honing etc. This hone just polishes an already great edge.