I have used the Speedy Sharp on a Spyderco with CPMS30V. It worked very well. I don't think I have a harder steel to test it on.

I think the difference between the Speedy and the other carbide sharpeners (which I think are junk) is the Micro 100 carbide itself. I believe this is a link to the carbide manufacturer: http://www.micro100.com/

Anyway, I'm not trying to sell anything. And I'm not giving up my diamond stones. But IMO the Speedy is a handy problem-solver and all of my kits are going to get one.