I've installed at least 20 black. I play with the SS. It hits like buter and doesn't mushroom. I would say the S is about the same harndess as the Moori M or Molavia M. The Kamui M is pretty hard. Basically they are about one hardness level up it you normally play with Moori. All of them hold chaulk and mushroom less then Moori.
It is true about the same tip in Illinois plays the same in Vegas. Not true with anything else. I install 100+ tips a year. When I run out of my current batch of Moori M I'm done with them.
I buy them direct from Kamuitips.com but you have to be an installer.