I prefer synthetics for riding. It doesn't get as wet and dries much faster than wool. My plastic clothes have been a lot more durable as well.
I like wool in camp because it doesn't stink and feels better when dry. I always have a Polartec 100 fleece for chilly evenings and mornings, as a pillow case and camera padding. I've been looking for a similar wool pullover simply because I try to reduce the plastic getting to the sea every time I wash my clothes.