High warmth to weight ratio. I wore it under a non-insulated rain jacket for some spring snowboarding at Mammoth and overheated. Soft and comfortable. The hood and thumb holes are a nice touch. Sizing is off though. I'm 5'11" 160. Ordered a large originally and it was too baggy and long in the sleeves. Replaced it with a medium, which is almost too small - quite short, t-shirt sticks out underneath.