It would be exactly .4758473845643% more efficient when comparing it to something less efficient.
Flywheel - faster revving, less initial kinetic energy, less mass to rotate at high rpm. Good in 1st, great in 2nd, okay in 3rd, negiglable in 4th.
Clutch - It won't slip and take heat MUCH better! It's actually a hair heavier.
LSD - more parasitic loss, more power to the ground (being as both wheels get the power not just one when traction fails), BULLETPROOF.
