[Holyterror]

Brake fade is when the brakes become less effective as they get hotter. Brake components (pads mainly, I believe) will start to break down at high temperatures, and the materials that used to provide friction may degrade into lubricants. This is bad. OEM pads will be useless by 300 degrees (fahrenheit). The other, probably more significant, reason is hot gasses on the surface of the rotors, causing the brakes to float. Slotted rotors diffuse the gas more quickly, which is a major benefit.

The smooth braking action you're talking about is usually described as "linear" or "progressive" braking, and is a very desirable trait. Auto makers are putting more effort into achieving this than they used to. Go test drive a Porsche 911. Ferdinand's boys got it right some time ago. They use ceramic rotors, and they work. They're also extremely light. A very good reason to test drive before you buy.