I have some Buck Knives with this steel, and also some with the upgraded steel. 420HC is easier to get sharp but it also gets dull sooner...
You can pay more now for better steel or you can spend less money and more time sharpening. I really like my 420HC blades, but this year I used my ATS-34 Alpha, 119 special and a few other 420HC buck knives to butcher our deer this year. The ATS-34 did stay sharper longer, enough to warrant the higher price tag??? I will have to think on that!
Buck Knives 420HC is good steel, heat treated perfectly, it isnt like other companies 420 IMHO.
It also depends on a persons budget I guess. If ou have the extra buy the upgraded steel you wont be sorry. If money is tight, you cant go wrong with Bucks 420HC either. Also what do you plan on cutting with it? That will also make a difference.