Originally Posted by sparky

From some extensive reading:

Solid blank rotors = best heat dissipation, best for racing.
Slotted rotors = reduced heat dissipation, better bite and performance in the wet.
Drilled = reduced heat dissipation due to less material, faster pad wear, minimal cooling from holes, prone to cracks from excessive heat cycles, worst for racing.

I simplify but it's amazing the conflicting info out there.