It's actually a review of a material, not a particular brand -- merino wool. I love it! I don't love the price, but that is why God invented sales ! The material is light, has a great thermoregulation to weight ratio, is environmentally friendly (you can compost spent garments), and doesn't stink. It is also quite hydrophobic (water repelling) and resists being burned. Last, for the most part, it isn't itchy (long sleeve things can be, at least for me). The only downside I've encounters is a mild lack of durability. It is prone to getting holes, especially garments made by Smartwool. With that being said I love Smartwool's run shorts and t-shirts, and small holes don't bother me. They make you feel like you are running naked with some mysterious support in all the right places. Icebreaker's stuff seems to be more durable, but I like the fit, feel, and cut of Smartwool's products better.