Wool is definitely not as durable, although one year in, I have only managed to wear out one wool T-shirt and one pair of wool socks. I suspect most of my wool stuff will last many more years, but YMMV.
I have Ex-Officio briefs, and I find them a little constricting, if you catch my drift. Wool stretches out more so is usually more comfortable. However, the durability and stink-proofness are pretty good, better than under armour and the like. I bet Arcteryx is better, but at the price point, it sure as hell better be.