Has anyone ever worn a souwester hat? I've seen them in photos for years, but have never seen one up close or tried them on.
I have. Short story: They work, and are very comfortable for their intended use: Working outside in rain and wind.
For hiking I'd say you're better off with a Goretex anorak with a good hood. When you're hiking you need better circulation than the sou'wester hat can provide.