Good camping stores should have self inflating mats on display for people to lay on and test (often on top of stones etc) so if you can get to a store then you can try them out for yourself.
Personally I hate the darn things but that is just my opinion and there are lots of people that love them and find them very comfortable. I think sleeping position plays a part in comfortability too.
From what I have read, Thermarest and Fat airics are possibly the best makes.
Thanks for your replies- I have been reading up about the fat airics and am very tempted, as when there are 4 of us blowing up air beds it becomes a bit tedious.
We have the DreamTime XL's and they are the Dogs Nuts, more of a sleeping system than just a matt, they comprise of a large matt, with foam insert, which is encased in a fleece cover with tough vinyl base, that can be zipped of for cleaning, OK they are expensive, but two fastened together make a superb double bed, best nights kip I have ever had in a tent, anyway I was in COSTCO today, and had a look at thier self inflating matts, at 180cm x 70cm x 7.5cm they are very good value at £17.61 inc VAT, but not in the same ball park as a similiar sized ThermaRest when it comes to quality, the old adage, "you pays your money", comes to mind.
We are SI mat fans, and I sleep on my side a lot and prefer them.
Soemone mentioned thiness and not being so comfortable - there are thicker ones- 7cm or more, but I still prefer a thinner SI mat - I generally use a 3.5 cm one now to an airbed - I've never liked airbeds and I've tried a fair few, uncomfortable and in a tent often cold unless you faff about with extra insulation for them.
I've tried a Drematime, and whilst it was comfortable enough, it certainly wasn't worth the money IMO. and I don't have a problem sleeping on my currrent mat
I have three Thermorests, the thickish "Base Camp," the thin "Prolite" and the green one in the middle. I find the Prolite perfectly adequate and the Base Camp more than adequate, particularly if you wrap it in a cotton sheet so I'd see the "Dreamtime," even at £125.00 as a bit over the top.
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