I've cut a well treated D2 blade with it. It takes more effort, but it will cut it. Think of it like a saw blade going through oak instead of pine. It just takes more effort and time, but it will still cut the oak.

I never really replaced mine when I lost it. I have portable sharpeners, but all the sharpening I do these days is planned for and done on a diamond wheel and a rouge wheel and a grinder motor. I've never had sharper knives that hold an edge as long as mine do now.