I was in the market for a lightweight jacket, and stumbled across this model. This post even showed detail and comps relative to others, and this is by far not the most expensive of its class. I ordered.
Roll forward a week and it arrives, my first trip is to walk 5 blocks to a restaurant to meet Cindy and friends for dinner. I'm wearing an undershirt, cotton button up shirt that's thin, and this jacket. As I exit my building, I feel the temperature that declined through the day - it's around -10 to -11C. My face feels it, I put my hands in my pockets right away, and think to myself how many blocks it'll be before I feel the chill go through to my chest.
As it turns out, it didn't. This thing is ethereally light and surprisingly warm. I thought it would be "ok warm" as in "gee it's so light, I'm surprised it provides even enough warmth to keep the chill out for a few blocks" and that it'd be a better -5C jacket. I was surprised. And impressed.
A week later I did similar walks downtown of 6-7 blocks in -16C. If my hands were out to answer my phone, they'd be cold in 60 seconds. I was warm when walking with the wind, and just got the slight chill walking into the wind. That well exceeds my warmth expectation for something this light, and that again was dressed in just an undershirt and a cotton mens dress shirt, not really purposeful heat retaining layers.
It's 135g, or a quarter the weight of my MEC Uplink Hoodie. It doesn't have hood or pockets, and it's not really a weight thing per se, what it really means is it can pack to virtually nothing as there's very little mass present. With a water proof case I could very easily put this in a bike jersey pocket if we think we'll finish ahead of luggage arrival on the cooler days at the Yak Attack.
Nice piece of textile work Montbell!