Actually I am still using one unit, the MRC, to control all of the reversing loops. This is working fine for now but I need to install separate A/R units in case "traffic" gets heavy on the RR.
Maybe it's high time for a basic track plan diagram. Here's a plan showing the reversing loops: The Upper loop on the right, the Lower loop near the middle and the Turntable loop on the left. These loops are controled by DCC auto-reversing units and are "transparent" to anyone running trains. A/R units from MRC and Digitrax cost about $25 and are worth every penny. I use both brands and I think that the MRC A/R unit is the easiest to install. The Digitrax unit can be adjusted for sensitivity and looks more sofisticated.
