Other bridges do the same thing (a Steinberger bridge does although the saddles are kind of "free floating" when not locked together). From what I can remember (the G&L site, G&L's site, probably has the whole story - or if not then The GLDP does) the bridge is massive and inset into a route in the body to make "fuller contact" with the body. Then the locking mechanism makes the entire assembly more rigid to fully transmit the string vibrations to the body & vice versa. This is designed to give the same type of performance as through-body stringing while allowing the strings to be terminated at the bridge.
