This is a great piece! I use it for winter running. It hasn't been that cold yet, but I'm able to wear it down to 30 degrees w/ just a wicking t-shirt underneath, and 15 with a lightweight long-sleeve. It breathes extraordinarily well and I find that it blocks the wind very well as well.
I actually have the grey and liked it so much I went ahead a bought another in the red!
Great work Stoic!