While I love my diesel pusher and would own nothing else, the gas RV's really make a lot better sense in many cases. When diesel cost $0.60 to $1.00 more per gallon you won't make up the difference in fuel economy.
The problem with gas RV's is the noise and ride (by comparison).
That doesn't mean that the ride is terrible or the noise is unbearable but, by comparison, the ride, handling and noise level of a diesel pusher is far superior to a gas model.
What's important to consider is how much driving you will be doing compared to how much parking you will be doing. Hope that makes sense but if you plan a 3,000 mile trip over the course of 6 months you will be parked much longer than you will be driving. However, if that same trip will be done in 2 months you will be driving a whole lot more.
Once you are parked, it makes no difference whether it's a diesel or a gas RV. At that point, the only important thing is the floor plan.