In reply to Denni:
> Badly written as a helmet does actually fit under the hood:
The interesting observation in your quoted article is the suggestion that 2 of these would be warmer, lighter and more flexible than 1 typical belay jacket (ME Fitzroy etc)
I've been having thoughts along the same lines and will be experimenting this winter layering a Primaloft Alpha vest/gilet with a Primaloft Alpha hoodie, giving up to 80 (Alpha) fill in the sleeves and up to 160 in the body vs 100 (Primaloft One) fill in my standard jacket. The breathability will blur the operating boundaries and extend functionality, yet would allow me to pack both hard and softshell and dump the big jacket for lower weight, more warmth, greater flexibility and weather resistance.
On the other hand, there's nothing like a cosy big jacket for that summit cuppa when you top out, is there?