Different feature sets. Vapor will have the asymmetric quarter, the Recoil tongue, the injected eyelets, the Aerofoam liner, etc. that are in the Vapor line now. The Supreme has the flexible tendon guard, the Reflex tongue, the symmetric quarter, more traditional eyelets, better wrap on the foot, and other Supreme features. This is being done so that the type of skate you can get is no longer solely determined by the fit you need.