I have to say I'm a little perplexed by all the hand-wringing over how breathable these windshirts are. Am I the only one that sees my wind shell as part of my insulation system while on the trail?
That is to say, I use my windshirt to stay warm. So to me, this means that I'm never going to be all that hot in the wind shirt (and therefore won't be generating too much sweat), and if I do happen to get hot, I just take the windshirt off and let the wind cool me down. Is this not what everyone else does?
I've got a wind shell that fails the "breath test" that was articulated earlier in this thread, but I still find it plenty breathable for moderate hiking with a pack.
I also like that it will warm me up a bit when I put it on and I know a big part of that is due to the fact that it's not super breathable. So I guess I see this as an advantage rather than a disadvantage (one that also, incidentally, makes the jacket more "windproof").
Now I can understand if you are all runners and are sweating like crazy under these things and routinely getting all clammy, but I don't understand the problem with moderate hiking in these things. Maybe I just don't sweat as much as most of you?
Again, whenever I get hot in my wind shell, I just unzip it or take it off. It's easy enough to take on and off that I don't really think too much about it anymore since it lives in the outside mesh pocket of my pack anyway (always within quick reach).