I found the 154CM on the Muk to be not terribly difficult to work on my belt sander, but I started at I think 160 or 180 grit, as I was reprofiling it to a convex edge. I never tried that particular steel by hand so I can't give any insight into that, but I didn't notice much of a difference from other steels.

I should point out, though, that all of my belts are pretty new, and that probably had a lot to do with it. I also am a lot less likely to notice the differences on a sander where reprofiling is measured in minutes, as opposed to doing it by hand where it's measured in hours.