I've cut a lot of both, plus the exotic alloys on state of the art equipment. I've always been able to cut C/M a little more accurately. Not so much numbers, but is micro finish.
SS steel tends of develop hard spots, and also tends to vary from lot to lot number. Where as a typical certified lot of C/M will be extremely consistent in machining. Another issue with steels (all types) is the constant changing factor. You know what C/M is going to do from the get go, but with stainless steel it often becomes an adventure. I used to take a piece of metal from the same bar I was going to machine, and literally make a few cuts on it to see what it was like. Some cut very well, and others were nasty. You get into the high dollar exotic SS steels, and you find them to be a little consistent. Yet you still gotta learn them.
I've honed a lot of SS steel, and it's OK to hone. Still nothing like C/M. I can hone C/M within a +/- .000050" window without too much trouble. I can also do the same with stainless, but I also have to fight that last couple tenths to get there. Another thing to think about is not in numbers or even micro finish, but contour shapes. Both cut similar shapes and contours till you start looking at a max radius of .005" or less. You often have to go back in there and grind to get there. Trust me; you want to avoid doing this. Yet there's nothing in a rifle barrel held to this thank God. The worst thing I ever cut with stainless steel was gears. Cut well, but seemed to constantly be moving around. Hard to hold a near perfect involute. I ended up leaving .008" all the way around, and ground them. To do over (I gained some knowledge) I'd have left .003", and shaved them and honed .0005" off them shave job.
One thing stainless steel does very well, is to be cut via wire EDM. Doesn't seem to change much. Only worked it over a couple times with a sinker, but results seemed OK.
gary