Slotted and/or drilled do little to nothing for a street car with any semblance of a modern pad compound. Slotting and drilling of rotors is purely for appearance (despite what some of the places selling drilled/slotted rotors will tell you) and will actually significantly decrease the life, and significantly increase the chance of catastrophic failure of the rotor under heavy usage conditions.
So, buy them if you want them so you can look cool, but don't buy them for the supposed "performance" benefits.
