leroys_45,
Sorry, I didn't formulate my think enough precisely. I meant that XT 80 steel is easier to sharpen than high-speed tool steels.
No, I had no problems with some knives with high-speed steel or tool-steel blades. I use DMT diamond sharpeners and GATCO ceramics and both can sharpen each blade without difficulty. Simply some steel can be sharpened with more efforts and another with less; it's the reason of my comparison. However this comparison is very subjective, the effort when sharpening knife depends not on blade steel only.
As to your comparison AUS-8 with XT 70 and ATS-34 with XT 80 - generally you are right. I tested edge retention cutting cardboard: XT 70 blade (Katz Black Kat Lightweight folder) and AUS-8 blade (Timberline Special Service knife) both were sharpened for hair-popping sharpness and then I started to cut wave-cardboard sheets. I made 10 cuts with one knife and 10 cuts (with the same length) with other. After each 10 cuts I tested shaving ability on hair on my forearm or leg. The AUS-8 blade lost shaving ability first but difference wasn't too large.
I repeated the same test on XT 80 blade (Katz Special Forces knife) and ATS-34 blade (BM 710) with the same result: ATS-34 lost shaving abilities first and also with minimal difference.
Please treat these results with good deal of distance, I can't to warranty the same cardboard properties, sheet per sheet.
No, I don't know the composition. In March I'll meet Mr. Keith Derkatz in person on IWA'2000 gun show in Nuremberg and I'll ask him this question.
Provo, UT, is the native city of North American Arms revolvers and pistols - great mini-guns, but it would be a bit off-topic, sorry ;-))