What is more awesome is when you have electronics that can sense the engine motor for idle, crusing and acceleration and control the fan and heater with 3 settings each. This is what a DCC decoder can do, no chuff and minimum smoke slowing down or going downhill and hard smoke/chuff when accelerating.
Dan, that does sound like the ultimate smoke set up. Although not quite as sophisticated as what you just mentioned, I like the way MTH would have a flywheel attached to the end of one of the motors. The flysheel had black and white stripes on it and a photo sensor do detect the speed of the motor and would adjust the smoke accordingly. And you knew that they would work right out of the box.