I probably qualified as "mustachian" before the term was coined.
He's a very good writer. I think the secret of his popularity is that he could rehash/rebrand old financial ideas in an engaging & compelling way. His car-related posts are great, and I've read most of the non-car-related ones too.
I also like that he's a gearhead, and ecomodder at heart (eg: made a hitch-mounted cargo box for his Yaris).