I have both the Alpine and the Summit versions and the latter is a fair bit warmer without being uncomfortably clammy on the bike. I hate down jackets on the bike as they just aren’t suited for riding unless it is absolutely Baltic. The only time I have worn one was on the summit plateau of Ben MacDui.
Mountain Equipment do a Switch Pro jacket with Polartec Alpha which is another cracker as it is designed for ski mountaineering. I have one and love it.
It would be great if bike clothing companies took a leaf out Rab and Mountain Equipment’s book. Design features like under the helmet hoods aren’t great. If I am cold or damp, the last thing I want to do is take my helmet off and try and squeeze a hood in. It’s the same with short cut roadie style jackets which leave your stomach cold when you are off the bike standing up.
If they are charging mountaineering kit prices, the design and quality had to match. Otherwise, you end up paying for an inferior product based on brand image.
Cheers
Sanny