I have a Filson wool vest about 20 years old and its held up great. Still looks good enough for semi-dressy occasions. My 35 year old Filson cruiser coat is still good to go. For a couple years I tried the synthetic fleece thing, but got my wool stuff out of mothballs last year. No more fake stuff for me, its wool all the way from now on. At my age it seems like I feel the cold more than I used to, and the poly-fleece stuff just does not cut it. I also swear by wool lined gloves, and my wool watch cap. I also use the wool socks from Cabelas.
The only disadvantage I can think of is that with wool, you have to have it dry cleaned once in a while. No big deal. It can be brushed pretty good, and soiled spots can be cleaned with cool water/woolite. For off season storage use a cloths bag to hang it in the closet with ceder chips or mothballs. Its worth the bother.