I have a Sony review camera system. Nice thing about it is that the system can be turned off if you wish but it will come on when the rig is put in reverse. Sometimes you just get tired of that constant movement in your peripheral view. While I do have a Class A, i have a towed and like to know when I can safely make a lane change after passing some one to my right. The camera is aimed so I can see my ladder on one near side and both side lanes at the rear of the towed.
Often I am alone while angle parking at the storage yard and can virtually see the rear bumper of the Winnie.
In campgrounds, I use the rear audio so the DW's instructions are clear but there are too many motorcycles with loud(read that as unauthorized/lawful) exhaust that can really startle you.