Rating: 4 / 5
I agree with everything Jonathan said above. Pairing this with a merino wool top is just sublime.
I'd just like to add that I find the fit to be much slimmer and somewhat shorter than I expected. I'm slight of build, but I can barely get a Men's Medium over my shoulders. (In other clothes, Medium is usually a bit baggy.) Once it is on, it is fits pretty well, but has little shoulder room. If you aren't at the smallish end of a size, I'd suggest going up one size.