Hi Wayne,
We only wanted one fuel to deal with which was diesel. No other stops to make or worry about. We purposely didn't want propane on the coach. Not all coaches give you that choice.
As far as reliability regarding diesel vs. propane, I really don't know. I was more concerned about MY convenience obtaining the fuel. When we had a rental unit a couple of times before purchase, it was hard finding propane and you had to wait for someone else to pump it.
We are generally from 'plug to plug' as we don't boondock very often (once a year in Quartzsite for 3-5 days). Friends that had propane in a Sprinter Class C had to get propane every 3 days so they had to break camp to refill.
Our diesel tank has 150 gallons so I could run it quite a long time if I had to run the genny (only needed for air conditioning on a constant basis). Our battery bank will run everything else that would require the generator 2 hrs. in the morning and 2 hrs. in the evening to keep the batteries topped off.
Good luck,
MM.