Geoff,
I've used Wool Power (Ulfrotte) wool for about five years now. I wear the socks every day, even in the summer and I wear the wool undershirts almost all winter. I have one on now. It's the best clothing of any kind I've ever found for staying comfortable.
I used Sitka Gear's 90% jacket and pants this year and in the colder weather I was just fine with a 200gram and a 400gram shirt, a down vest, and my 90% Sitka Gear jacket. For pants just the Sitka Gear with 200gram Wool Powers was fine for even the coldest temps this season. (Temps as low as the teens.)
The stuff is expensive but WELL worth it!
AND, in all this time I've not had to replace a single piece. It lasts a long time AND it hasn't shrunk when I washed or dried it.