I have had one of these for about 18 months. I have used it in all weathers and it has never let me down. I stay warm/ comfortable - never cold or too hot. If I am working hard, it just shifts sweat away without you noticing. When I have got wet I don't get cold - it just works really well as a base layer. It washes easily and dry's quite quickly. But unlike 'plastic' garments, you can wear it for days and its doesn't get wiffy - a great bonus on a multi day trip. I wont go back to 'plastic' wool all the way!