Dave
Assuming we're referring to rotary bonnet or brush methods here, then the obvious things that come to mind are the restricted space to operate machine in domestics (not to mention stairs) and the possibility of pile swirling, although you can groom out the latter if it's not too deep. Also, the possibility of friction burning to domestic polyprop may be more noticable if it were to allowed happen, compared with the tougher commercial loop piles.
Pete (JS2)