I've never found anything heavier than 100wt fleece to breathe well enough for me, unless I am sitting dead still in very cold conditions. Guess that's why I prefer the R1 hoody to heavier stuff.
Question was about base layer. 200 wt aerowool is nothing like 200 wt fleece.
The Patagonia R1 IS a base layer, 100 wt fleece. I guess the Sitka is "aerowool"
Sorry for the misunderstanding.
