Well, I have done side by side testing of a Benchmade M-2 AFCK, an ATS-34 AFCK, and a Spyderco Military in CPM440V. For toughness, I cut through a lot of comm cable, electical cords, and tin cans. All three blades performed pretty much equally, dulling about the same amount, no visible chips from the edges. So I got mad and decided to dig my way through a 2X8 with the two AFCKs, stabbing them into the board and prying out chips. I managed to break about an eigth of an inch off the tip of the ATS-34 blade. I only managed to bend the tip of the M-2 blade, and easily bent it back. I didn't do the prying with the Military because I wanted to sell it rather than damage it.
For edge holding, I whittled away at a big piece of particle board with all three blades, taking ten similar cuts with each blade in rotation, waiting for one blade to differentiate itself as the winner, and one the loser. It never happened. I whittled away for hours, hundreds of cuts, and all three continued to perform equally until I gave up.
I liked sharpeneing the M-2 AFCK the best. It has a very low tendency to form a burr, and produced a nice fine edge with medium effort. The ATS blade was less abrasion resistant to the stone, but forms a significant burr that takes some extra effort to polish off, making it just as much trouble to sharpen as the M-2 blade in my opinion. The 440C blade took the most effort of the three.
Sorry, I didn't have a Sebenza at the time, so there was no BG-42 in the test, but my big impression from the exercise was that the differences in practical performance between premium cutlery steels are small rather than large. Reeve BG-42 is probably finer grained and tougher than production ATS-34 blades, but the actual difference in cutting performance is likely to be pretty hard to demonstrate, even harder if you compare BG-42 to ATS-34 that has been custom heat treated.
[This message has been edited by Steve Harvey (edited 30 August 1999).]