Shortest stopping distance is the only rational way to compare brakes. It doesn't matter what you avoid hitting although some objects are more valuable than others.

The post you refer to is riddled with errors.

Automotive brake discs are made of cast iron for very good technical reasons. They wear faster than they used to because of the pad material, not the cast iron. They reach discard thickness rapidly because they are made as thin as is safe to save fuel, improve performance and reduce unsprung rotational weight which helps handling and ride.

Silicon carbide is only used in carbon ceramic brakes (hence the somewhat misleading name), not cast iron brakes, and it is objectively clear that carbon ceramic brakes are not superior to cast iron brakes in road cars except from an unsprung weight perspective.

 

A Typical cast iron material used in aftermarket brake discs or rotors is grade GG25 or GG20 and almost all discs from Asia will use these grades and contain these elements.

Carbon
Silicon
Manganese
Phosphorus
Sulphur
Nickel
Moly
Chromium
Copper

More Carbon and Silicon produces a more thermally stable disc that is quieter, resists cracks , dampens vibrations better and handles heat better.

The above is an excerpt from a leading disc rotor manufacturer .

The brand name is not the issue , but what a cast iron rotor is made of .

 

http://www.theglobaljournals.com/ija...1_a111e_37.pdf

The variable proportion of carbon and silicon are very small and those of the other elements are even smaller. It seems from articles like this that small changes in the amounts of carbon and silicon can make a difference to disc wear rates and other performance characteristics. This at least implies that you get what you pay for with discs and not just pads.