"Putting poly close to the skin and wool on the outer seems like an interesting concept Tom, but I'd need to try it."
In the absence of any significant data, I'm toying with the idea of playing lab rat with this one. As you said, it's an interesting concept, but miles ahead of the old Duofold cotton wool version that I cut my teeth on when I had no clue what I was doing. I expect it'll be a matter of justifying the expense of an additional layering component when I just sprang for the Cap4 Hoody.
"With materials as thin as base and most midlayers there are too many variables, and the relevant differences so small, for empirical data to be very useful. Anecdotal is probably the best we'll get in most areas."