Could Be the EU Regulations?
I just tested my Miele U1 Auto Eco against my S7 Salsa and the Auto Eco is both louder and more aggressive when it come to the brushroll. It seems like the bristles are stiffer and longer on the Auto Eco which makes it louder, but it does have more aggression too. I think this was done on purpose. Now whether or not it is because of the EU regulations or not I am not sure, but it does seem lime a design decision was taken as of late to make the brushrolls more aggressive.....even at the expense of a little more noise.
