SS line do not fail anymore than a stock line would. The SS lines offer a greater resistance to expansion which in turn provides a better brake pedal feel as they do not require as much fluid to fill. The problem noted on dsmbalk is that if a failure was to occur, it is much more difficult to locate the source of the failure as the SS will conceal the leak. That could be a bad situation if you were not to realize your fluid was leaking, but I am sure you would see puddles on the ground if something were to go wrong. This is generally true of any SS line for anything but it does not make them weaker.