Why use RCD's?

I think there are people who do it because they cant keep the hogs bayed or from breaking, but I personally perfer a rcd because even though I use mine as a lead in cd I like the diversity of a cd with good lungs and leg on him/her. When we have more than one cd and the right mix of dogs on the ground we cut them loose from 500 to 1,000yds out sometimes. Or like the other night the curs were split bayed after we got to the closer hog the bulldog broke loose and headed to the other dogs and it was 45 min until we could get there, alot of dogs would have heat stroked out by that time but my partners dogo was locked on no problem, walking back to the truck after that he was running around like a pup burning off energy.... so even though its rare it is handy to have the advantage when needed.