I have to agree with Paul's assessment, even more so since he is also carrying both models. The older Benchmite 310s are still out there brand-new and in their boxes with papers, but I really don't think you are going to notice an appreciable difference in the blade steel.

Also, from the Benchmade site: "154CM: An American made premium grade stainless steel originally developed for tough industrial applications. Known for its best all-around qualities, it offers great corrosion resistance with good toughness and edge quality...AUS-8: A Japanese made medium-carbon, high chromium stainless steel, which offers a good balance of toughness, edge sharpness and corrosion resistance."