I bought my 91 gallon RDS auxiliary tank for the convenience. I like not having to stop at a diesel station but once every four or five days while traveling every day on the road.
With my auxiliary tank, I eliminated my least favorite thing about traveling long distances: looking for a good place to refill every few hours.
The only time I damaged my trailer was trying to snake my way around in a too-crowded station. Now I refill mostly when unhooked and going out for dinner for the night.
Having said that, being able to buy the lowest cost fuel helps too.