I've heard all the raves about this piece for years and finally picked one up this winter. Now, I never take it off. This has been the perfect layer for the winter skin track. Typically, it goes over a wool base layer for the up, and then under a shell for the down. It has performed extremely well under falling snow, graupel, wind-sun glacier trips, muggy trees... external moisture blows right off, while the heat from within flows out. Even when its windy, I find I stay warm even though I can feel the breeze blowing through the material. The fit is great as it fits over the base layer easily and is long enough to stay in the pants/bib without balling up (I'm 6-1, 185 and I'm wearing the size L). The hood has also been extremely useful - keeps the bite off the ears and chin when needed, keeps the hat the head and still vents very well. The material also dries very quick if it gets wet. Interestingly, it doesn't seem to get too stinky either, even on a 7-day hut trip. Bonus.