Hi Chris, Let me know what you think about the Merino stuff. My interest is seakayaking and hiking, and I shall be using the Everwarm undergarments on a multi-day expedition this southern summer. I shall post an evaluation when I have trialled it under real conditions. Key advantages for me, apart from the obvious thermal qualities are that it is incredibly fine, like silk. It is non-itchy, which is a plus in a wool garment, and it apparently can be worn for days without too much body odour! Cheers, Peter Rattenbury