I have been hearing about how versatile a wind shirt (such as the Marmot driclime) is for climbing and now I'm curious. My question is, if I already have a fairly light hard shell with long pit zips, will a wind specific shell do much for me? Is it much more breathable and comfortable than a well-vented hard shell? I do most of my climbing in the N. Cascades, and I tend to bring a hard shell anyway for most trips longer than a summer day with a good forecast. I sweat quite a bit when I'm on the move; many times the pre-dawn start for a glacier climb is cold enough for me to wear a baselayer and a hard shell without generating too much moisture- but not always.
I'm a big fan of versatility with gear, but if my hard shell is doing almost as good of a job as a wind shirt can do, I don't necessarily want to buy another piece of gear and make my pack heavier.