In the five years I have been using my TRC unit, it has shut down power four times that I know of. It could be it shut it down more times, such as when I was away from the trailer.
If nothing else, I see these things as good insurance from a electrical safety standpoint for the humans involved. It could save a person from being shocked due to a miswired pedestal.
Of course it may also save some electrical components in the camper too, but that pales in comparison to it's value as a safety net for the people involved in the RV.