Re: Gas versus Diesel
I'll answer this way. We have now been fulltime in a 35', gas powered RV for 6 1/2 years and we have crossed many mountains with it, always towing a Honda, CR-V. We have not towed the Honda about 30K or so and before that we towed a Ford Ranger. A gas chassis does not climb like an equal size diesel but it does get there and not all that much later. If climbing power is a major concern, you can add a performance kit from Banks or Gibson that will greatly improve the climbing ability of the gas powered motorhome. The cost will be about $3K to do that. Modern gas chassis also now have the GVWR to have nearly as much or in some cases more carrying capacity as all but the highest priced diesel rigs. And you can get just as many amenities and as much quality in a high line gas motorhome as you can in all but the highest priced diesels.
The fact is that the diesel does have some real advantages over the current gas chassis, but not nearly as much so as was the case some years back. They usually have air ride which is much nicer than springs and they also usually have air brakes which are still somewhat better than on a gas chassis, although they too have improved dramatically. They also get better fuel mileage, but as you state, the price difference will buy a bunch of gasoline, especially since I know of no place that diesel does not cost at least $0.30/gallon and does gasoline. It does not appear that will change soon either. In addition, mechanic rates are always at least $10/hour more for a diesel and parts run nearly twice as much. Maintenance on the diesel may be less, but the cost will be at least as much.
If price is not a serious object, I would still buy a diesel for the nicer ride and the quite operation that comes with a rear engine. But the fact is that my gas powered motorhome is just as nice to live in when we are parked in an RV site as it would be if it rode on a diesel chassis. If the question is which is nicest, go diesel but if the issue is cost of operation, get a gas powered RV.