There is considerable difference between cross drilled and slotted brake rotors. A slotted rotor lasts considerably longer than its counterpart, as heat which builds up when braking automatically gets discharged. It is a lot heavier than a drilled rotor which means that it will stop in a short distance. The cross drilled rotor on the other hand is a lot lighter in weight. In wet weather it can get rid of water and have a better distribution of weight. Both types of brake rotors stop in a shorter distance than standard rotors. Normally these types of rotors are fitted to cars that are meant for some type of racing.
For more info, see Adjusting Air Brakes to Your Vehicle