I've been a 1" (2.5cm) Thermarest Prolite sleeping mat guy my for past 15+ years, used it every time I slept in a tent and found it to be adequate for the job. After a a few replacements I upgraded to a Thermarest Neoair Xlite, which was really light but I got no sleep as I found it very noisy and slipped off it all the time. It also took 21 breathes to fill compared to my ol favourite 4 for the Prolite.
So this time I tried a different brand and type of technology, Australian to boot, and I now have a new favourite the Ultralight.
I tried this mat out for the first time on a 0 degree night, and I have to say I have never been more comfortable. At 2" (5cm) think its very plush and I stayed on the mat for the night without effort. It has an R rating of 3.3 which equals or betters the past, so good for anything but sleeping directly on snow. I am not a cold sleeper, so if you are there are other thicker denser insulated models in the Sea to Summit range.
It has a large port for inflation and bigger one for deflation. However it deflates very quickly using the inflation valve, so care might be need if one has to adjust it. Perhaps because of its plushness it absorbed the lumps and bumps better. I often had to adjust the Prolite if it was too hard or soft, with the Ultralight I just filled it up and used it.
The mat comes with its own pump incorporated in the stuff sack, so no need to buy extra pricey accessories. Simply plug the stuff sac onto the mat, lightly blow towards the stuff sac, crunched the opening shut and push down crushing the bag. Two or three of them and the mat was full. I see this as a real advantage for limiting mould growth in a mat. My prolite never got it but I could not see inside either, however my wife's Neoair is moulding badly, you can see what is happening from all the huffs and puffs to inflate it. I'm not sure what heath issues may arise from this, or if it effects the mats structural integrity either, bit it doesn't look good.
I bought the regular size 183cm x 55cm, its a little lighter at 480g compared too my Prolite's 570g, and packs a little smaller as well. I have to say the Neoair is hard to beat if you just look at weight and pack size. The material on the Ultralight seems somewhere between the rather heavy looking Prolite and frightfully thin Neo. Time will tell if the Ultralight will last, but to date we have had good service from the others. One thing I think this mat will struggle with is fitting into my ol Thermarest chair, st
RRP is around $190, but on sale I picked mine up for $159 without much effort. Happy sleepinghttp://seatosummit.com/product/ultralight-insul-mat/