After doing more research on the subject since this seems to be a recurring topic and I shouldn't rest on last year's information...

I conclude that I don't know the answer. However, I have found some interesting info. SS apparently is a PITA to grind and smiths say they need special equipment. So that explains the lack of spine work and singing razors. Just not worth the time and expense. SS may be more brittle, but that wasn't conclusive, so I think the difficulty of grinding is the problem. Bill Ellis engraves his SS razors, so its not impossible.

Assuming both blades are used regularly and stropped and oiled...theoretically the one with the higher hardness will hold its edge longer. I am not sure when high martensitic SS alloys became widely available, but apparently they can take a good hardening. So, if SS can take the same Rockwell hardness as carbon steel, the edge retention is theoretically the same. Add the corrosion resistance and I would conclude SS is better.

So, does anyone have a rockwell hardness rating chart for the high quality stainless alloys?