The motor with the cable puller just seems to solve a problem that was never there, just putting a big bulky box in and still have the problems of stretched cables and so on, the in calliper idea seems quite good imo, our college tutor was saying he went to a talk on them and they said they are only about £120 to replace a whole calliper so not that expensive really in comparison. When held on handbrake and the car is off it adjusts the pressure in the caliper ever 5 minutes to make sure it wont roll away when they cool down and so on, but the diagnostic equipment for them could be a problem for most garages i would have thought, cant do and disk/ pad changes i suppose..