I have polypropylene in three weights. The light is a pair I got from Walmart about 20 years ago and it has worn like iron. The middle and heavy are miitary issue. Poly stink isn't a factor as I'm not especially stinky by nature and come home and shower and change every night. I've been looking at silk, but according to online reviews there's a lot of phony stuff out there, as well as a lot of cheap and shoddy goods. I suppose I'll have to go with some L.L. Bean or the like to get good stuff. That, with some good merino over it sounds like the hot setup.
Polyester fleece seems to be replacing polypropylene somewhat, but on me it builds up moisture on the inside and it takes a long time to wick away. Fleece shirts are the same way which is why I'm replacing them with light wool Pendletons.
