Gary & Scott,
On backcountry hunts I normally pack 3 sets of syn long underwear in different weights. Over that goes Sitka 90%, or Cabela's Micro Tex. I always have a lightweight woven midlayer insulative piece with me, as well as a sweater-jacket filled with either down, Primaloft, or other light and lofty insulation. I often pack a pair of insulated micro-fleece pants for cold mornings. My wind and rain shell is currently a 3 year old set of Sitka Nimbus. This is a true ultralight rain shell, with no middle layers or hanging liner. It dries quickly and stuffs to softball size. I'll likely have other pieces along for the hunt, but that's the main sum of it. Notice I never carry a coat, parka or heavy jacket. I must add that a search of my duffel bag might reveal some merino wool long underwear, or maybe Ulfrotte. I still always wear syn uw next to my skin.
This year I do have a set of KUIU to try. I think it will be very much like the Sitka, but different in some ways. I have grown to love the tight and water repellent outer finish of softshell garments. They stretch...they repel water and mud...they stay cleaner...and they are very comfortable.
Scott, as far as durability goes...I've never had much issues there. I believe wool would win the day however. Maybe I'm a fussy hunter (I don't really think so) or maybe my age has made me patient. I don't charge through brush or give my gear extremely rough treatment. I tend to treat good gear with some care, so it survives for future use. I know my Nimbus might shred if I crawled across a shale slide in it. I'd sacrifice it to get a shot at a ram, though! I know guys talk about the advantages of wool, and I understand them. Synthetics have just as many, if not more, advantages for me vs wool. In my mind the "wet clothing" issue is way more theoretical than actual. Like goose down...guys say it gets wet and is worthless. Maybe, but in 30 years of using goose down I have yet to get it wet. I have gotten synthetics very wet, and they did not chill me one bit. The wicking nature of today's syns is amazing, as is their fast-drying characteristics.
I like the rugged nature of tough wool. I like the way it looks. I like how I feel sneaking through alders with Sleeping Indian wools on...top to bottom. I've got plenty of pics to prove that wool has helped me kill game. When I "went" synthetic, I made a concious decision to weigh out all the important qualities (and negatives perhaps) of wool vs synthetics. I did it with an open mind and I avoided letting traditional thinking affect my mind. I'm all for tradition of course, but I'm a hunter first and foremost. I go with what works best for me on any hunt.