Gas vs diesel isn't much of a debate. You can always buy a smaller or less capable truck for less and pay less to maintain it. For me, I've seen enough gasoline RVs on the side of road that didn't make the passes to know that I'm willing to pay more for durability. Most of those failures from talking to people are busted hoses or transmissions from the Gasoline engines screaming to maintain speed over the elevated passes.
For the record, my diesel SRW got better mpg than my current DRW diesel truck, and that was a good tradeoff to haul the camper. That being said, I just bought a used SUV to handle some of the uses that the SRW could do. But, the SUV is way smaller and is can do things the SRW couldn't do like park in small parking places which unfortunately is a consideration for me.