Any idea if the hood would work under a helmet? The brim has me concerned, but I can't tell how big or structured it is.
The brim on the Strato has some lamination and I don't think it would work well under a helmet. You should check the Atom LT Hoody (I know it's a different category)-same thermal value, but better weather resistance and has a low volume hood designed to work under helmets. Epsilon SV hoody works over most new helmets and has similar values.
I have a Giro G10 helmet and I'm able to wear the hood under my helmet. One thing though, I shave my head so I don't have any hair to take up space.