Not all race car technology transfers well to street cars.
I've tried drilled rotors on a number of cars, and they usually wind up stress cracking.
Also, tehy reduce the surface area of which the pad rides on, so they to some extent lessen the stopping ability. But, they initially grab better so folks tend to think they've had an improvement when it may or may not actually stop the car faster.
Wilwood and Baer have done their homework and exempt from the above.