I have one of these in the playroom funnily enough
Do they hoover up okay - yes and no
A hoover lifts the loops up but it is easy for stuff to get stuck in them.
If I had a proper dig through I'd probably find raisins, playdough crumbs, acrylic fingernails, shards of cat litter and possibly the odd sherpa.
No seriously they do hoover up fine, as long as you actually hoover 
I sometimes take the hoover pole and just suck around in a random fashion and that seems to puff it up and get rid of any major debris 