I forgot to discuss when, where & why drilled rotors have a place.
For the type of competitions you're running, if ...
a. The track is short or has tight corners
b. The difference in corner speed & top speed is significant
c. Your lap times are affected significantly by your ability to accelerate & decelerate
d. Your brake temps are well within the safe range from overheating
e. You already have small diameter rotors
f. The drilled rotor is priced modestly for your application
g. You are serious about your maintenance program
h. You are serious about competing at the top level
Drilled rotors make sense then, because:
1. You can afford to replace them at the first sign of heat stress
2. The lighter rotating weight will accelerate & decelerate quicker
3. Improving your lap times
AutoX doesn't build much brake heat at all. So I love drilled rotors for AutoX competition as long as your maintenance program is good.
Same with other short track racing. We ran them on the rear of our 2550# NASCAR Modifieds, where the temperature window was around 400° or less.
P.S. Since I wrote this before having my morning coffee, I expect I'll need to edit this later.
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