[jmatta]

A 996TT is a very heavy car and will generate a lot of heat under braking, especially if the driver is not highly experienced in using brakes for short periods of time (may or may not be the case here).

I agree with Lucky's comment that those aren't throw-aways just yet, but I'd certainly keep an eye on them for further cracking. Slotted is a better way to go for track cars with plenty of air ducting. I've been tracking 911s for years and have always considered rotors throw-away items and would purchase fronts by the half dozen.