My two cents -
I bought one unit from RVwholesalers and saved a ton. Had warranty work done without issue several hundred miles away. Some places gave me the "did you buy it here" line, but I simply moved on to someone willing. There are also some companies out there that are not brand specific for repair work. They may be authorized Dometic service centers for example, but are not even RV dealers. Recently had an awning fixed by such a service center.
I also bought a 5th wheel 2 years ago and the local dealership matched the RVwholesalers price. I went with the local guy...........