Edge durability how about expert opinions?
As a beginner I have shaved with less than a dozen different straights. Even with my limited experience it is obvious the steel in some razors is special. I have a little swayback Genco which takes an edge very easily and seems to endure without much more than stropping. It is easily my best shaver. I have a Filarmonica DT #13 which takes an incredible edge very easily and holds it nearly as well. There are other I have which will get as fine an edge but can't seem to maintain sharpness through more than a couple of shaves. I am referring to very sharp as they all remain shavable but the best maintain that "fresh from the stones" keeness through repeated shaves and stropping while the worst is notably degraded after one shave.
My experience with knives indicates edge durability is a quality which is found on individual examples or rarely some models which have undergone careful manufacture or QC as in individual or custom made.
It seems there are fads and passing fancies to favor certain razors but it appears to be more a matter of fashion than function.
If you have shaved many razors which ones stand out as have especially durable edges with the kind of shave ability which requires only rare visits to the stones?