That's a pretty good amount of weight shaved off. I hope you don't hack up the car for weight savings..lol. But I wouldn't mind seeing more mods that would shave some weight off. Looking good you guys.
power gain (or recover rather) depends on the inertia and speed of rotation. so for the same rotational speed, if the weight is at a big radius (wheels) its big power savings, if radius is small (driveshaft..) small power savings.
While the Polar Moment of Inertia (Radius) is extremely important I believe the "Rate of Acceleration" is much more important than the "speed" of the part in question.