What your expaining is temperature variation. Properly slot an 8" rotor and experience the braking bite from over heated brakes were as non slotted rotors will fade. A big brake assembly can handle and maintane a consistant temperature, mostly low.
Big solid rotors are predictable and consistant, to the driver, this is important. Brakes get hot and cooled throughout the track, a rotor that maintains heat consistency is more predictably and doesnt carry a phantom brake issue that a once hot rotor, cooled before the next turn adding to un-judgeable/predictable braking. And like most racers, budgets interfere with selection of gear, ...solid parts barn choices. The 10x better braking from slotted over solid is truth. Bigger rotors do not require slots to aid in fade resistance because of its size able to keep a narrow temp band. The braking size assembly to wieght to be braking ratio is idea and able to maintain a narrow band of temperature while the smaller tiny assembly will heat up faster and cool fast creating a broad spectrume of temperature. ..in turn making them unpredictable....especially initial grab followed by fade. Maybe slots for the track is not idea but perfect for your every day driver. Take the tiny Gt rotors and put them to track duty! Youll say nope, they fade because they heat up to quick....brake fade! Also cool to quick, but a lighter assembly, gyro rotational weight is reduced, and the intial grab from a small rotor is a plus, but the down fall is spectrum of temperature. I dont want to argue and we both can "believe" what we will with our very own experiences. Slot improve braking...period.