Is this a disk brake only? I'd want to understand how it adapts to an out of true condition on the rotor, and more importantly how it adapts to pad wear (I'd like consistent braking "feel" throughout the life of the brake pads). I'd want a warning if my pads were at the end of their life.

I understand the reliability calculation, but it seems a more likely failure scenario is loss of power to either the transmitter or receiver. What's the fail-safe in this case?