ok, i'm not really suggesting good buy to layers, but...
example 1
http://www.youtube.com/watch?v=nrPbTkcsuyw
example 2
http://www.youtube.com/watch?v=cQo7dWS4GV4
i am aware that i can model everything on one layer now, but it would be very difficult to work on the model. that is why a "detail cube" system would work better than chopping the model up and putting it on layers.
the model should NOT be chopped up!