Well I'll just put a word in for going with the thinner versions. My current one, like the one before it, is only about 3cm thick inflated and I get on with it fine. I sleep on my side and it keeps my 12 stones cushioned and insulated from the ground perfectly well. I can't help thinking some people converting from deep blow-up airbeds are thinking they need to go with the thicker (= bulkier) self-inflating type when they don't need to really