Having used a boar for half a year I recently got a Simpsons Berkeley in Best. This is a wonderful brush for me (travel and face lathering friendly). It feels very soft compared to the 'scrub' a boar gives, even well broken in.

My question: Does a Simpsons brush in Pure give more "scrub and backbone" then the softer Best?? Or is it just a lower quality grade of softness?