I'm currently using slotted cross-drilled rotors on one of my daily cars which I sometimes use for touge runs.

There isn't really any improvements in braking performance compared to plainface rotors. Like other said, it's good if you always fade your brakes like in racetracks but otherwise there really isn't any upside to using it on the street. In fact, on my car, the brake pedals lost it's linearity after switching to x-drilled/slotted rotors.

On the downside, using slotted rotors might even introduce loud, deep humming and vibrations when slowing down from high speed, again, something you might not want on your daily street car.

Of course, it also depends on the brand and material of the rotor. But my 2 cents is, if it's braking performance you are after, maybe try better pads, fluids and steel braided brake lines first.