In all my outdoor clothing experience, nothing beats wool.
It just won't stink, and doesn't mind being wet.
I think it comes down to specifics............
There's synthetics & then there's synthetics, as with wool I don't think you can generalize that broadly.
Wool is great, but so is this stuff & it's way tougher & doesn't smell (far as I can tell anyway).http://www.swazi.co.nz/product-category/mens/
I suspect frequent washing is a bad idea.......... for outer wear anyway.