I think the ECF requested it to see if we could use it for the British Championships, but we had a list of features we wanted, and many of them never materialised.
At Warwickshire, we have two arbiters trained on Swiss-Manager who do all of that, while our floor helpers collect the results on a clipboard and hand them in to the Swiss-Manager arbiters at the end of the round. That also gets around the children who occasionally mess up filling in result slips. At Worcestershire, we only have one Swiss-Manager arbiter, since the event is small enough to cope.
Actually, I think the hard part is setting the tournaments up initially. Once you've got the tournament started, putting in the pairings and results is fairly intuitive.