We had new wool carpets in the autumn, our vacuum cleaner (Dyson) picked up a lot of pile for the first few weeks (I expected this with new carpets) but it is still picking up loads (if I hoover the whole house the drum is over half full of pile) and the carpet does look a little over brushed in places. If I drag the brush backwards over the carpet it doesn't seem to brush up as much pile, so I've been doing this for now but obviously it's not ideal forever 
Can anyone with pure wool carpets recommend their vacuum cleaner? I want a decent one, just not one that slowly trashes the carpet
. It's annoying as the Dyson is only a couple of years old and was fine on previous non-wool carpets...