This is an interesting discussion! Bob's observations about stainless merits some further comments. First of all, I have no prejudice against ANY kind of steel, provided its used for what its intended to do. People often say "high carbon tool steel" VS. "stainless steel". Well, the right grades of stainless (for cutlery applications) IS high carbon, and sometimes they contain more carbon than their non-stainless counterparts. The reason stainless steel got a bad rep in the cutlery business to begin with, is that the manufacturers used a lower grade of stainless that failed to hold an edge. People got burned and swore off ALL stainless. For example, take the 440 series of stainless. If you buy a blade that is marked "440 stainless", beware...because there are three grades used for cutlery: 440A, 440B, and 440C. If there are no other markings, its probably 440A, which only barely holds an edge for any length of time. But its cheaper, and saving a buck is all some companies care about. The only really good grade as far as I'm concerned is 440C because it contains at least 1% carbon, which is what makes the blade hard and take/hold an edge. If the maker wants to let his customers know exactly what they're getting, he should be marking the blade with the actual grade, not some generic term. I know Bill Buchmann used 440C, the best grade for that series, and Bill made some fine knives. Some manufacturers also use the term "surgical stainless". Well, there ain't no such thing. Ask a mill to run you a batch of surgical stainless steel and they'll scratch their heads and say "Huh?" (probably 440A again...)
The point is, each type of steel (high carbon tool steel and high carbon stainless) have their own unique advantages and disadvantages. You can heat treat high carbon tool steel, such as O1, L6, 5160, using special techniques and get an almost indestructible blade that holds an edge very well. Its more forgiving in heat treating i.e. if you make a mistake, you can take the same piece of steel and start over again. Bob already mentioned the disadvantage...it rusts. You can sharpen your head knife before you go to bed and have the best possible edge only to wake up and find it is duller than the night before. Any moisture in the air (on in your knife sheath) will collect along the edge and corrode away (on a microscopic level) that nice edge you worked so hard to get. Of course the big advantage for stainless is that it resists rust (in the right environment, such as close to the ocean, continued exposure to the salt air will even rust or pit stainless). You can get stainless just as hard or soft as you want, just like the high carbon tool steels. Stainless' disadvantage is that its not very flexible as to heat treating. If you do it wrong, it won't be the same the second time around. I use ATS-34 for my blades, and sometimes 154CM (ATS-34 is a Japanese copy of Crucible's 154CM). They have a Rockwell hardness of 60. It's a great steel and so far I've had nothing but compliments on my head knife blades. Using green compound to strop them(never use red or brown, they're not intended for steel!!) they stay sharp for a long time.
Now pick your favorite steel, make sure its heat treated correctly and what's left?...edge geometry. Other members mentioned this in this thread. If you don't have good edge geometry, good steel and heat treating won't make any difference! I agree with those that favor a tapered, convex (Moran, or apple seed) edge), like that on an axe. All my experiments with edges for head knives confirmed that the convex edge cuts through leather better than either a flat grind or hollow ground edge. But even convex edges have to have the right geometry. There's definitely a "sweet spot" on the edge angle that just glides through leather. If you're off a degree or two either way, it just doesn't cut as well...but once you find it, you can really tell the difference!
Terry Knipschield
P.S. Glad you like the knife, Bob !!