The volkl grip is less rectangular than the head classic (tk82 and TK76 pallets). I´ve been playing prestiges for 1.5year and now switched to the C10 Pro. The Volkl Grip is, IMO, something in the middle between Head and some other brands (more square).
The rectangular handle (Head) seems to work better when grabbing the racquet with a continental grip, so it feels comfortable for serves and volleys. I can hit great flat serves with this grip.
I can take a pic later between a Volkl, head and prince buttcaps if you want