From the Golfsmith Tech Dept. -- they are designing drivers to beat the USGA by hitting it high on the face (equates to hitting down with driver).
"The Comp 450 will be a little longer for on-center hits but the 650T is longer when the ball is struck just above the center of the face. The Snake Eyes 650T has a reactive cup face which is .2mm thicker in the lower 60% of the clubface than our uniform face thickness designs (i.e., like the Compressor). The upper 40% portion of the face is .5mm thinner. The thicker lower face allows for the clubhead to be measured as a conforming driver to the USGA while the upper portion flexes much greater than our other designs. Since we are promoting ball contact higher up the face we are able to make that portion of the face hotter, but have to thicken the lower portion to meet USGA COR/CT rules. "
"The Comp 450 will be a little longer for on-center hits but the 650T is longer when the ball is struck just above the center of the face. The Snake Eyes 650T has a reactive cup face which is .2mm thicker in the lower 60% of the clubface than our uniform face thickness designs (i.e., like the Compressor). The upper 40% portion of the face is .5mm thinner. The thicker lower face allows for the clubhead to be measured as a conforming driver to the USGA while the upper portion flexes much greater than our other designs. Since we are promoting ball contact higher up the face we are able to make that portion of the face hotter, but have to thicken the lower portion to meet USGA COR/CT rules. "