If I had a gasser, I probably would not have purchased an EW, but diesel engines and trans parts can be very expensive, so I bought an EW through ExtraRide. According to Cummins Coach Care facility, they are the easiest to work with and get approval on parts and labor.
I am very glad I purchased this for our DP because in the first year, I had to have both fuel pumps replaced(leaking fuel)to the tune of almost $3000. Shortly after that the generator kept shutting down. Turned out the over heat temp sensor was bad and labor and parts for that was over $500. A year later the fridge needed a new cooling unit to the tune of $2200(parts and labor).
ExtraRide paid for all of this without any negotiating or trying to deny anything. I am definitely money ahead, and I have 3 more years of coverage left on the policy.