I bought a small SUV custom conversion camper 2 years ago. Before that sleeping was either on the ground (open air) or in a backpacking tent.
I have to say that now that I have aged a bit I appreciate the 3" foam pad over the 3/4" backpacking foam pad. Not having to deal with lumpy ground and/or clumps of grass makes for a better sleeping experience.
For the last 4-5 years most of my camping/exploring has been in the winter. Having a camper/indoor space is really nice when cooking and just hanging out, especially during inclement weather. I'm 6' and can just stand up in it.
The guys who built the camper really made it utilitarian (rubber floors, formica walls) and the layout is great - lots of storage and a panorama of windows. It drives 2, sleeps 2 and eats/drinks 5 without feeling too crowded. Based on the G Wagen platform it does great on the dirt; 90% of my travels are offroad. It's my mini mobile condo!