I think this is appropriate again here:
"My choice to change our folding knife blade steel to S30V was thoroughly thought through, as was the selection of RC hardness 58-59. I was privileged to be involved in the development of S30V with the metallurgists at Crucible Steel – they asked what attributes I wanted in a steel and they delivered. At RC 58-59, the blade will hold a good edge and will be easy enough to sharpen. One of our tests resulted in S30V cutting 14,000 linear inches of e-flute cardboard before notable edge wear against 12,000 for BG42. I have been completely satisfied with the performance of S30V" (
http://www.bladeforums.com/forums/showthread.php/730951-Some-words-from-Chris......)
Some people will agree with Chris logic, others will not. Unless one is a metallurgist one can only speculate on his choices IMO and he feels it serves the intended design of the knife correctly. Heck, I still remember when ATS-34 was seen as the ultimate supersteel. Until the day a steel comes out that will never rust, holds an edge no matter what and can be sharpened on a piece of toilet paper some will never be happy.
For whats it worth. An old Spyderco steel chart I have (around 2006) shows they heat treated S30v between 57-59 so Chris cant be off that much with his HT if one goes on HRC numbers alone.