Actually he is incorrect about the chrome-molly barel lasting longer than stainless. Stainless steel is harder than chrome-molly and does not wear as quickly. However it is alsomoredificultto manufacturer an accurate stainless barrel than it is a chrome-molly barrel. So there are trade offs.

Keep in mind that stainless doesn't mean that it is stainproof. Stainless steel will still rust is neglected.