Jim,
MCE used then too. In most of the drive with DBR, I've always seen a mechanical overload with the contactor. Personally I always setup the overload protection in the drive as well. I will set the drive 2 or 3 higher. The function is there and I like the redundancy.

And yes, I've had them fail. The signs that led us to the DBR were the car shooting past the floor and/or tripping the overloads...