Janni, the hat section is not a huge savings compared to the over all weight of the rotor. The diameter of the hat is no more than 6 or so inches, but in a way it's a good savings, but I can tell you this much, 1 pound off the rotor beond the hat section, throughout the 14 inch disc, would be more effective than the 3 pounds off the small hat section, roughly. Not just heavy are these rotors they are huge in diameter.
If proper material is used the disk portion could be lightened up. These rotors are just to big.
If your not tracking the car, we could get by on a much lighter, and smaller diameter rotor. We may risk warpage, under extreme conditions, but the car will still stop well. A bonus is gained in braking on small light rotors. This sort of counter effects the downgrade in brake size. Large heavy spinning objects take much energy to stop, due to momentum.
Has anyone noticed the diameter of the Z06 front and especially rear rotors. Extremely light weight, and small inertia factor, as it's at least a full two inches smaller in the rear. That's not a slow car, and it's doe's not have a poor brake system.
Bottom line, (4) 14 inch monster rotors that weigh a ton, is absolute death on accelleration.
Only is this boat anchre brake system exceeded in overkill, by the over weight oem rims on the car.