I'm a big fan of Gore-Tex; however, I've had mixed results with Gore-Tex in sub-freezing temperatures (dry & cold). It breathes, to a point, but I find the 2-ply doesn't breathe quite enough to keep me and my insulation comfortably dry. Yet, my DW uses her 2-ply all winter.

There seems to be a general consensus that 3-ply performs better in cold. This is certainly what mountain climbers prefer. With 3-ply, if you get some frost forming on the inside, you can brush or shake it off. With 2-ply, such frost would be trapped between the loose inner liner and the membrane.

The XCR 3-ply looks like fascinating stuff. Expensive, but I think that will be my next Gore-Tex.