The way a disc works, is by dissipating heat and it does this two ways. First of all the pad mates to the face and through frictional contact dumps the heat and the hottest place is on the face of the disc. The heat then wants to move to the cool centre or radiate off away from the face. So my making the disc a capable at creating a lot of air through the eye to the low pressure part of the disc, it feeds the air much faster through the veins which becomes the core, the cool centre. What happens is the heats wants to equalise itself into the cooler centre. The the more effective you have this pump, the cooler the disc stays.

If a disc casting is interrupted by either a hole or a slot you create a stress point and creating a stress at that point, thus the disc will fail. Any racing disc that has been cross drilled or slotted, you see small web cracks forming.

Also you are interrupting the low pressure area trying to force air across the eye, so if you drill holes in the disc dace you are eliminated the ability for the air to through the veins as it wants to come out the holes. And what this does, stops the disc becoming an effecting pump.

Reason why you can buy discs now with either cross drilled or slotted discs as it looks cool when it was used years ago in racing. Because the pads then where made of asbestiosis they had a coefficient of friction or the mew of the pad was low, something like .3, well now it has doubled the coefficient of friction, as the pads now are better.

Pads keep in mind that if I gave you another 100bhp, you would expect it to burn more fuel. Its the same with a brake pad. If you have a good brake pad its going to dust and if you have a brake pad that does not dust, you have a brake pad that does not work. Meaning you would have a low co efficient of friction. Thus you would have to push harder on the brake pedal. This maybe what you want, but when most cars are under braked, the last thing you want to do is take it away.