Took the words out of my mouth John!
Tony it could be you have a harder one than most folks
![Cheesy :D](http://www.cleanitup.co.uk/smf/Smileys/classic/cheesy.gif)
But my poly scrub brush, after being run-in enough, is fine even on domestic wool carpets
As suggested the "shampoo" brush looks like it is more similar to the one I have, maybe that's the problem?
p.s. if you lower the handle height it helps combat the problem of the machine trying to throw you around