Those Jerba things look awesome but they are £4300, wow, I spent half that on ours and it works great. Although only the kids sleep in ours, it seems odd to convert a van and then sleep in the roof. The interior of the van is nicely insulated from sound and cold, ours is just a lovely place to sleep whereas the canvas bit above rattles like a tent. BUT you get the interior space to carry kit, so I can see the benefit. Not sure that I’ve helped much!