Slotted is pretty much the way to go for the 'average' driver who is looking for the increased performance + longevity. X-drilled+curve vained is probably better for the more race oriented driver who doesn't care about longevity past their next day of sessions & wants max performance. Drilled rotors will get radial cracks, slotted just tend to get the regular surface cracks any rotor will get with high temp use.
Later
"Only two things are infinite, the universe and human stupidity, and I'm not sure about the universe." -Albert Einstein
When was the last time you *really* did something with your Z to call yourself a Z enthusiast?