Usually the term "expedition weight" is reserved for the base layers that have the most insulating quality. I have some older heavy weight (the weight that is one less than "expedition") Duofold that are thicker and do a much better job keeping me warm in the so far mild Midwest December of 2011. So as far as my quarter of one hundred samolians goes, it was a waste. Yes they are useable but no they can't replace my old and tired Duofold expedition weight thermals. My outdoor activity level is standing and walking. Next time I will try Sierra's expedition weight.