"Surgical Stainless" is 420, 420HC, and/or 440A. All of them are very good blade steels. The heat treating, however, may not be as good as the steel is. Just depends on the company producing it. For example, I have a late-production Uncle Henry Pro Trapper. It is stamped "Schrade+". That steel wasn't a special steel, it was just their name for whatever stainless they used. At that stage of their production, it was 420HC. Earlier on, it was 440A. My knife holds an edge well, and is easy to sharpen. I have a Case 2 blade Copperhead with "Tru-sharp Surgical Stainless" blades. It is probably 420 or 420HC. It takes an edge well, though it is a little bit fussy about getting it on, but does not hold an edge as well as my Uncle Henry, Victorinox SAK, or any of my other good pocket knives, whether stainless or carbon steel. It is a pretty knife, with blue jigged bone handles, and is all-around a better finished knife than the Uncle Henry. I carry it a lot because I like it, but I also carry a stone because I know that if I have to do any moderately serious cutting with it, I'll be sharpening it when I'm done. I have blades in 154CM, S30V, 440C, D2, 1095, W2, L6, and other tool steels. I have made knives in several of those blade steels.
Gerber, I don't know what kind of blade steel they use, but it is a quality steel. I have had and used several of their knives. Some of them were fussy about taking an edge, but they all held it reasonably well once it was there.
What determines whether a blade takes an edge is the person applying it. I can put a razor-sharp edge on a piece of copper, but it won't hold it at all because it's too soft. What determines whether putting the edge on is easy or hard, how long the blade holds the edge, and how tough the blade is, is the heat treating. Most makers, like Case and Boker, do the heat treat on their non-stainless steels more effectively than on the stainless. Most stainless steels have a more exacting heat treat requirement than basic carbon steels, and it's just trickier to get it right. My next Case blade will be carbon steel, what they call "chrome-vanadium". I may get a Queen Cutlery in D2 just for fun, because I've never had one, they make a pretty knife too, and I like D2 steel. Makes a really good knife.
