Have not read all posts so sorry if this is a repeat, but:
Sunbeam makes shoddy rheobus/rheosmarts With not much force the plug connector, which is attached with a little plastic and glue, came right off. Wtf. One of the heatsinks was also wobbly. Piad $12 for a 4-knob version and was glad I didn't pay more. That said, it did work while it was alive. But know that rheos just crudely reduce voltage by resistor so they eat more power than PWM-based controllers.