Sail shaping balances the speed and power of a sail with control and handling. Shaping lower down in the sail will produce a little less power but increases manoeuverability. Shaping higher up in the sail creates more drive and low-end power.
In the performance oriented sails this extra power is easy to control due to the profile stability supported by cams and tube-battens. In the manoeuvre and wave oriented sails, low shaping distribution provides uncompromised manoeuverability.