The difference is that the utility companies will have to give the money back if they have over-estimated - without to onus being upon you.

PRS seem to work like a estimated tax demand - it is up to you to prove to them that their demand is wrong. You can see why such an approach is attractive and I am sure that many other bodies would like to work like this.

It is clear from the 30% discount PRS offer to any music shop who complies with their demand that they will try and take any cut of anything rather than have nothing at all.