fc3spro.com "A cantilever suspension suspension system removes the damper and springs away from the wheel hubs and runs them remotely via a bell-crank system.  By moving the damper and springs, unsprung weight is greatly reduced - the wheels and tires react a lot quicker to changing road conditions." 
  
I could see the benefit of such a system, but less unsprung weight with a higher center of gravity. Additionally, the rear suspension of 240sx is already independent, so there's less of a gain to say doing the same for the Z's Chapman strut or the FC's semi-trailing arm setup. 
  
That's beside the point considering, that as you've all said, the quality looks debatable; Interesting no less.