Don't get me wrong. 440x is fine with me. I was just commenting on the quality of Rosarms and RMK. If it came down to price I would pick a Rosarms. I collect RMKs. I can see the differences. Rosarms is a nice substitute to consider. They are actually very cool knives. As for the sheaths, I just get one made out of Texas for my Rosarms. I've decided that personally I really don't want Rosarms to change their sheaths. That would just jack up the price.
As for 110X18, as far as I know it is mainly a ball bearing steel. Makes for a good knife blade. The only complaint I have about 440C is that most have enough carbon deposits in it that it makes it hard to sharpen very well. That is one of the reasons Buck switched from 440C to 420HC. You have to be someone, like myself, that started learning how to sharpen on 440C and 1095.