Now the last thing is the stone is pretty muddy, which may or may not be your thing cause you gotta find something to do with leftover mud or wash it off. The mud can be used to finger polish on the knife -- you can use cork or rubber or a cloth and polish surfaces, which is pretty cool. But it will release grit/cut differently.
To use the stone, add water until it darkens and you have a little water that stays on the surface and sharpen. More water means the sharpening takes place on the stones peaks and valleys. Just enough water to form a viscous film means you float and only sharpen on the peaks, and the peaks are smaller and more uniform. This happens because the viscous film acts to make the scratch pattern finer and more shallow. Too little water and it will feel too sticky, or dusty, and jerky in motion while sharpening.
The higher performance Jnats have more extreme desirable characteristics or a more complete set of characteristics:
they are finer, cut faster, leave a nicer or more uniform finish, are bigger, are prettier, work on harder steels, are softer yet fine at the same time.
I tried the Jnats at JKI a while back and they still feel nice compared to the more expensive ones I have. It doesn't really matter to me much; if I had only a muddy finished from JKI, I would be fine . . . my continued curiosity didn't really get me anywhere nicer, functionally, in razors and in knives.
Uhh, people recommend to not soak jnats, so don't do that. Temperature cycles and wet/dry cycles can lead to cracking, so people say to avoid those, but as a weird aside, the older synthetic stones that I let go through these cycles cut better in speed, feel, and finish than ones I let soak, so that's something I experienced as well, however damaging it is to the stone.
You can check out Jon doing a comparison of synthetic (gesshin 4k) and natural (suita). The suita should be a little harder than the oouchi.
