I've sharpened S30V and S35VN many times on my SM. I didn't find it too hard at all. Not quite as easy as VG-10, but not so difficult, either. I've even reprofiled an S30V blade that was dull and way too thick at the shoulders of the bevel with my SM. I used mainly the gray rods, and ended with the white rods. The reprofiling wasn't fun, though. I used the SM because at the time, I was worried about doing something I might regret by accidentally removing too much metal from an expensive blade at any one time. It took maybe 20+ minutes at a time, over a period of several days (not every day consistently, but on and off). This was years ago, and I wanted to see if it could be done.
Not ideal, maybe, but if you're maybe concerned about mistakenly removing too much metal and aren't in a hurry, with some patience it might be a slower option for some. For some other 'super' steels, it might no work well at all for that.
Jim