"Probably to the dismay and disgust of the armchair theorists, I'm starting to think that the "actual owners/shooters" of DR's in 375 belted may be very happy with their rifles."

Yep, I'm one of them - happy with my Merkel 375.

The whole thing is a beat up - and most DR shooters who overload their guns won't admit that they overloaded them,
prefering to blame it on the gun / manufacturer.

I reckon it would take 20 - 30 rounds to take any DR off the face.