This piece is well made, not too bulky, and , I imagine, provides the same excellent insulation as the Stowe vest. My issue was the sizing unfortunately. I am almost always a medium and measure up very closely to the medium specs in the Woolx size guide. The medium Rainier was too big around the mid section. The small was too tight under the arms. I'm 5'10", 160, lean , not big. Same issue with the Stowe vest. Sized down to small and it's a great fit for me. Customer service in both case was top notch. They immediately sent the new size so I could compare to the one I had then asked me to return the one I didn't need. The replacement arrived in a few days, no expense on any return. The Stowe vest is great as a top or mid layer, breaks the wind and provides non bulky warmth which I'm sure would have been the case with the rainier as well. Excellent products. Have the turtleneck and henley both in medium and the fit is great.