Rating: 4 / 5
My primary use of the Nano is as a quick pull on/warm up layer for breaks either backcountry skiing or snowshoeing. For this purpose the Nano has been excellent. It provides a surprising amount of warmth for how thin it is and can be managed with gloves on. After two seasons as a winter warmer it seems to be holding up okay. I didn't give it the 5th star as the build quality just isn't there (seam stitching seems to be fraying and if you look closely you can see insulation sneaking out through the seams).