I am using the Valvetronic electronic exhaust valves and Valvetronic actuators with stock active exhaust mufflers. The only problem is that the actuator has decoupled from the valve a couple of times. Last time, I added super glue, and it hasn't happened again. It is a pain to align the actuator...
Are they hub-centered? I have spacers on mine, and I don't think they are a big brand; they are just hub-centered. No strange noises so far (knock on wood).