David Smail has an interesting restructuring of class on his book The Origin of Unhappiness. He describes the upper class as the Distal class, as they are able to make decisions from such a distance way from the classes below that it's difficult to immediately follow their effects back to our proximal reality. The working class becomes the Consumer class, as their social and economic power is limited solely to consumption. Lastly, the middle class becomes the Mediater class, as they have just enough power to mediate decisions from the class above to the class below.

I've found this description to be more relevant to a post Reagan/Thatcher economy than more vaguely defined terms like PMC.