Hi, berreez,
Here is the answer to the real question I think you are asking:
Take a test drive in both a gasser and a diesel -- accelerate up a hill. (If there are no hills in your part of MO, maybe an interstate on-ramp will do the trick.)
Which do you prefer:
1. Enjoying the view and conversing quietly with your copilot as the engine rumbles dimly far behind you.
2. Waiting for the crest of the hill to arrive while the engine roars/screams next to your knee.
Now, granted, this comparison is a bit exaggerated for dramatic effect. But, the point is that you really have to experience it yourself to appreciate the difference.
Although very little of your travel may actually be spent traveling uphill, the differences between gas and diesel coaches will still be felt while tooling along, hour after hour, mile after mile, on flat roads.
After all, motor-touring is much more than just dragging a rolling motel room from one place to another.