This helps with blood circulation- I don't do that, nor any kind of physical exfoliation,as I tend to broken capillaries.
I don't like anything scratching my skin ( I know that the brush is very soft, i mean generally!
). I use a rx retinoid, and if I needed extra exfoliation I'd use a BHA (salicylic acid,only thing that can actually get inside a clogged pore and exfoliate) or an AHA (which can't get inside the pore, but nevertheless exfoliates dead skin cells away).
Nice info here:
http://janssenbeauty.com/us/skincare.html and also on Paula Begoun's site.