My 9" Bosch is actually very nice to use. (I just bought another which i think will be just as good.)
But put a 4" cup brush on it and you need to hold on for dear life. Absolutely awful thing, the vibrations could shake your limbs off.
Some of these wire brush cups are off-centre or not true when you get them new, I have binned a couple because of the vibration. need to be careful if using as vibration could break your grinder spindle and the cup fly who knows where.
