You are just moving the mattress around for some reason, aren't you?
It fills up so much of the van that it must be hard to get to anything. You'd have to put the roof up to turn over.
How does so much weight high up in the back affect handling?
Hilarious! On a serious note though we have been using an Outwell dreamboat 7.5cm self inflating mattress on ours and I sleep better on it than my bed at home. Concertinas up easy and rolls up out of the way when not in use Probably one of the best things I have ever bought!