It's interesting, yes the steels are very comparable as ZT points out. But I wonder what are the factors when ZT says m390 is hard to obtain. Is it literally not readily available in mass? Backlogged orders? Or did the price of the steel increase and therefore current retail prices couldn't be sustained? "M390 has slightly more silicon, CTS-204P has slightly more tungsten and manganese; all other elements are the same." Is the silicon ingredient the problem? (cost/availability). Why didn't ZT go with cts-204p to begin with? Was it because m390 had more name recognition / hyped up marketing? After all this new steel is USA produced and seems like they would have preferred the "made in america" steel to begin with. Overall I agree its small potatoes. Just curious.