I am in love with the Ibex underpants! I used them on my x country ski trip and they made a big difference as to how warm my azz was. Definitely need more pairs.
Today I wore my hooded Shak skiing, with a Craft base layer and my Go Lite jacket. It was perfectly fine, at 15 degrees with a brisk wind. I found the Smart wool base layer to be the best for winter activities, but when I wore it with the Shak, the whole thing felt itchy. It must have been the combination of the 2 things, because I love the Smart Wool base layers. Need more of those, too!