Different type steel altogether. SR77 is a shock steel, able to withstand lots of shock and lateral force on the blade. The 154CM is a premium stainless, often used in folders. It has superior edge holding and corrosion resistance to SR77, but not quite as tough. 154CM is a very good steel for this type of knife. Dan posted some pics of abuse testing Busse's 154CM, and it is plenty tough enough.