"people feel that there is a functional advantage to crossdrilling. The only advantage is cosmetic."
I am a bit confused on this one .... if this is so, why are Mercedes, Porsche, BMW and many other performance manufacturers installing them as standard equipment on some of their high performance cars?
This just doesn't sound right.
Cracking originally came about from non-chamferred edges on the drilling. Since then, all drilled rotors of any quality have the addition of the chamferred edges. Porsche reported this on their race cars in the late 1960s.
Here is an interesting site: Cross drilled