In reply to John McKenna - Rockfax:
I've spent whole weeks on these and, honestly, I can't stomach an airbed or other inflatable mattresses, in general.
These MondoKing things are actually so comfortable, I've spent many a sleepless night in my real, proper, grown-up, in-the-house bed contemplating going downstairs to fetch mine and setting it out on the floor as a more comfortable option.
Mine is about 18 months old and doesn't leak, too, which is practically a record for anything which air goes in, in my opinion.