well for one, you don't waste time pulling down the rope, it adds up, there is no rope in your way making it less awkward and you can put the unit on a bit easier/faster, cows kick off units and cluster remover lifts them after a while making it look like cow was milked out properly, then you have to go back and if you have an "if" about it at all then you put it back on cause you wonder "did she kick that off or did machine take it off:001_huh:" where without ACR's you KNOW that if you didn't take it off she probably not finished. cows will catch on rope easier than just the pipes and so it makes them kick off more often.
and they clutter up the parlour alot, without ACR's parlour is more open and just a nicer place to be.