To begin with Zett wear is extremely comfortable technical clothing to use as a base layer. I am more comfortable with Zett products then my standard Merino wool under layers. This says a lot as Merino is a high comfort standard. Once skiing, the fast wicking properties of the Zett products are a big asset as other products often become saturated. Being wet and in subzero temperatures is unpleasant. And finally from a performance standpoint, i have never experienced anything like Zett before. I ski faster and i feel stronger. I let my friend try a Zett t-shirt and he claims "it's like being spring-loaded! My chest feels so open; i breath better."