Do you have a link to any studies done on the heat dissipation? I haven't ever been able to find any. Even Porsche admitted on their site a few years ago that the drilled/slotting were only for dissipating water vapors during wet track sessions, with no mention of the cooling effect. (This has since been taken down). I believe Stoptech had/has a similar article on their site.
Is this the StopTech article @phsycle - The "Warped" Brake Disc and Other Myths of the Braking System? This is the one I had in mind when I wrote the post above.
Interesting read by a GM lead engineer - Mirza Grebovic, Investigation of the Effects on Braking Performance of Different Brake Rotor Designs. Not a definitive study by any means (it appears to be a personal paper), but interesting nonetheless. (Google it).