A self levelling SIM? Not sure mine is that thick that I would notice but then I use it on top of a camp bed. Find it's more comfortable than my bed (although maybe that's cos I don't have to share it!)
------------- 2015 April: Polstead, Suffolk. May: Two Acres, Ely. Waveney River Centre and Whitehall Farm, Norfolk. Aug: Howstean Gorge / The Quiet Site / Fron Farm / Cae Du / Trevayne Farm - BOOKED!
Remember the thicker the Sim the more adjustment you have on its hardness. I let so much air out of my 10cm that when I kneel on it I'm just about touching the floor but when I sleep on it it's soooo comfy.
------------- Gary Cross - The masked camping guru.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.