Not the lightest.... Not the smallest but.... hundreds of nights sleeping on my Thermarest Prolite 4 have proven it's durability to me. The NeoAir looks like something in my future maybe.... I live by the replace it when it breaks theory most the time... Might be a long while before that happens.

Slept on Glaciers many times.... Don't think it gets much colder than that with outside temps 20 below F....

Your clothes do help despite what was said above. Nothing dramatic but it does help.

I'd rather tour with to much pad and to little bag than the other way around....