I really don’t understand the comparison to camper vans, surely the nearest comparison is a plain old tent?
I did think that originally but I have changed my mind. A normal tent is far more convenient for a holiday, the main advantage of a roof tent is that you can instantly pitch then instantly drive away in the morning – that’s what you can do with a camper van.
Once you start using it as if it were a standard tent with all the paraphernalia then it starts to become significantly less convenient, I reckon.