Depends on your needs. We started with a gas MH because we could store it in our back yard. Jumping from a truck and trailer we weren't sure we would be happy with a motorhome, a gaser is cheaper to start with.
However after a few years, gaining confidence we realized a DP would be a better choice.
We figured out the storage issue, and realized we love having a motorhome. We found a local shop for all mechanical needs.
The rear diesel keeps ALL the engine noise in the back, 30 plus feet away, no more shouting at each other. The air ride removes most of jostling and noise from the road expansion joints and such.
It's quiet, smooth and the mpg is better than the gas. With gas we ranged between 5 to 8 mpg depending on wind, hills and speed, I drive the speed limit. The diesel averages 7.9 to 8.5 under the same conditions.
We have no regrets. Good luck with your decision!