I think the advantage of ECU coolant temp control is that increased power demands particularly with a turbo engine allow anticipation of increased coolant temperature rather than the "closing the gate after horse has bolted" action of a conventional thermostat. It also removes dependacy on the calibration of same.
Clearly the disadvantage, in this case, is when it doesn't work you need a new radiator (or three).
Is it simply a matter of incorrect settings or is there an actual failure of the system ?
hope I'm wrong though!