I agree that most of the positive dealer interactions go unreported. Here's one that just happened to me. On this summer's trip, my water pump started working poorly, putting out water in spasms instead of a smooth flow, with lots of air mixed with the water. I checked the pump for loose hose connections and checked the water filter and was still stumped.
I took the fifth-wheel to my dealer to "fix that lousy water pump." They found the problem: a valve that you open for winterizing (when you want the pump to suck in antifreeze) was partly open. (I keep a plastic tub of cleaning materials under the sink, and near that valve. My moving the tub around must have turned the valve.)
The charge: nothing. Heck, an unscrupulous dealer might have told me that the pump was bad and I needed another.