I loved my slotted rotors.
No holes though.
I went with a grooved and dimpled design for the car. Results thus far is they don't warp. Can't attribute that to the grooves and dimples, probably more metallurgy - much better than OEM's. Normally, I go through a set of front pads on about a 2 year replacement.
Reading through the various comments on this and a similar thread I posted there are a lot of "cons" against drilled, slotted rotors that leave me somewhat confused.
Taking all the cons stacked up at face value I am struggling with a few of the concepts presented as they appear to conflict one another:
I can grasp that slots and holes reduce surface area on the rotors and could indeed require more pad pressure to induce a given coeffieicnt of friction resulting in a given stopping rate. Is that difference significant enough to matter? I don't think it is - everything I run with slotted and drilled or grooved and dimpled rotors has plenty of breaking system capacity to lock wheel/tire at will on dry pavement either race track or street.
However, it could be that the surface irregularity created by groove/slots, holes/dimples actually increase the coeffieient of friction by the nature of the pressure of the pads running against them when hard breaking. One of the posts comments on increased pad wear with grooves/slots, dimples/holes. So, these type of rotors cause higher pad wear while having decreased friction (less braking capacity/capability) due to decreased surface area? Huh? Is that possible?
I haven't ran them long enough to be able to compare pad wear. But, I can state that the amount of crap in the front wheels from brake pads dust hasn't increased with grooved & dimpled rotors. If pad wear were diminished by 50%, I would them change them out about once a year - doesn't take much more time to do front brake pads and purge old fluid, than to change oil/filter and clean and oil the air filter on the car. So, how big a deal is that if the wear argument is true? Quite frankly, I'm not yet convinced it is cuz there ain't no evidence of it on the front wheels.
Prone to cracking and failure in general - shorter life span? Again, experience with the racing karts over the past 8 years and no breaking system issues. All rotors are drilled and slotted. Just change pads when needed - never changed a rotor, never warped a rotor on the karts. Quality rotors are quality rotors and junk is junk.
Don't want to hijack thread or start up a flame war - but, there's my opinion and first hand experience.