When considering retro-fitting new disc brakes on an old drum brake car, what is the importance of the number of cylinders/pistons in the calipers? I have heard of benefits of "one is best" and "the more the merrier."
The single caliper system is simpler to maintain. When the caliper "floats" it equalizes pressure on both sides of the rotor. When it does not float, typically the inner pad wears out first.
The KH style caliper allows the pads to be removed without removing the caliper. This is why they used to be favored by endurance racers.
The big variables are clamping force, swept area, rotor mass and surface area, and the coefficient of friction of the pad material. Some pad materials are so hard, they need a little heat in them to work optimally.
I don't think running ΒΌ mile at a time will really stress a properly working disk brake system on a largely street driven car. If you have a terminal speed of greater than 140 mph, then I think it's time to look for something more substantial in the way of brakes.:read2: