I can't free hand worth shit (well, a little), but I can use a Lansky.
What company "typically" uses 420HC? Specs are specs. This steel has this much carbon, nitrogen, whatever, and this steel has this much.
420HC is 420HC. Sure they might actually heat treat the blade unlike some china made knives, but it's still the same steel. Two apples. One's grown with opera music and sunlight. The other is just grown in sunlight.
What's tried and true about a 420HC ht? I'll be the first to admit that I don't know much about knife making processes, but what makes it historic? To me, comparing a well heat treated 420HC blade and a poorly heat treated S30V blade (made a while ago in this, or another thread) is the apples and oranges comparison. Properly heat treat both steels and see what they can do.
I can't bring myself to believe that Buck has some "magic" quality in their heat treat that makes their 420/440 steel better then most. It may be better then say cheap china made blades, but it can't bring the steel past it's own abilities.