I just went through the same decision making. I chose a new 37ft gas unit. I'm retired so I move slowly and stay about a month when we stop. I know I will move a little slower up the mountains but that's ok with me. I have friends with DP's and I know they spend a lot on initial cost and maintenance. Everyone is right when they say they are quieter, ride smoother, maybe get better mileage, but when we are stopped I can't tell the the difference. In today's gas units they have more power then the old 454 ci engines and they have more storage outside. You have to decide what fits your needs, floor plans, and what fits comfortable in your budget. Good luck with your search.