Came across this:
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WHAT IS THE DIFFERENCE BETWEEN VG10, VG-MAX AND SG2 STEEL?
VG10, VG-MAX, and SG2 are three different types of advanced super steels that Shun uses to make our blades. In blades with Damascus cladding, the cutting corethe inner layer of steel that actually does the cutting may be made of one of these advanced steels. Blades with no cladding may be composed entirely of one of these steels. These three steels go far beyond the typical good, better, and best categorization. Instead, think of them as excellent, superb, and ultra-premium.
VG10 is a highly refined stainless steel with excellent edge retention and stain resistance.
VG-MAX has more chromium and vanadium than VG10, which provides even better edge retention and corrosion resistance, and enables Shun to harden the steel so it will take an amazingly sharp edge. VG-MAX is only available in Shun knives.
SG2 is powdered steel; this means it is even more refined than VG10 or VG-MAX and it remains more ductile (less brittle) even though it is very hard. It offers superior edge retention and corrosion resistance, with less chipping.
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Pretty confident marketing statements
I wonder what that 'hardening' process is (?).
One of the knives I was working on was a Miyabi brand, which is VG-10.
It was one of the harder ones to get a good edge on.
I also own a "Shun - Ken Onion", which is "VG-MAX Damascus". I have not tried sharpening it because I don't use it much - as I don't much like the feel of the curve of the blade.
Out of the box, it was scary sharp, and after the first time I used it (on a wood cutting board), I noticed a couple of very small chips out of it.
I wasn't doing anything hard core with it, just cutting vegs.
I think I still prefer old-school high carbon for refined kitchen work, or cheap 'commercial' blades for the rough kitchen stuff.
One of my favorite knives in the rack is my $12.45 - 10" Scimitar... not sure exactly what the steel is, but it is a breeze to sharpen and holds a pretty decent edge - for a few trips out anyhow.