Most of the Scout leaders in our Scout group use just a SIM on the floor, no blankets under them. Just the groundsheet, SIM and sleeping bag. They say they are warm and comfy.
In fact the cubs and scouts tend to sleep just on a simple foam roll mat.
I personally prefer my Coleman's Comfort air bed or my camp bed when I go camping but each to theit own.
We've been converted to Vango Trek SIMs for the family, combined with an Exped velcro strap kit for making two into a double. Given up on wobbly and deflating Coleman comfort airbeds, although served us well for a number of years. SIMs are easier, quicker (only a minute or two to inflate), avoid the need for a pump and comfortable too (just adjust the number of additional puffs to suit). They don't need toping up regularly and are fine on their own with a footprint, SIG and inner liner beneath them and just the sleeping bag on top. Our 2 moon pillows sit inside the hood of our mummy sleeping bags, so we don't need to cover the SIM with a sheet. We also have a couple of strips of that matting used to stop rugs slipping just in case we find ourselves slipping on a sloping site.
We store ours at home under our son's bed so storage expanded is not an issue.
We are definitely SIM converts!
For information the EXPED strap kit "EXPED Coupler kit" really works and is very easy to fit. Exped's own beds tend to be a bit deeper than our 3cm SIMs so I reduced the length of the small vertical section between the 2 halves of the stap by about half with a few stitches and the two SIMs stay nicely alongside each other without any gap or over-ride. Success! No need for a bulky double that is difficult to store.
------------- Love our set-up and need no more tents or gear, so trying to stop looking!
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.