I'm hoping only those of us in the know will notice the difference in the LED's/switch design. I'm working on a new project. In one room I needed IR control of a multi button controller, hence, six button PCS. In another room I wanted a rocker/load control and four link buttons, hence, US2-40. In the same room I have switches that don't fit in standard boxes due to the ginormous heat sinks. These are the PCS X version 1000 watt switches controlling T5 fluorescent lights. I've had to modify industrial switch plates to accommodate these beasts. I am seriously thinking of hiding the switches for the loads on the next project and doing all my room control with link buttons in the rooms. Cost goes up but aesthetics do to.