In reply to:
12W peaks times a 4 speaker setup brings the total consumption into a 48W range, well below the rated output for a receiver but about 50% of its rating, not 10%
You make some good points, but typical amps are rated at X Watts per channel, not total. Certainly depends on the amp. There are many different ways of expressing the ratings that can me misleading to some.
A decent amp usually denotes the Watts per channel rating with "all channels driven simultaneously into 8 Ohms at 20Hz-20kHz". Less desirable is the "driven with 1 kHz".
The other thing I've seen recently is an amp rated at 110 WPC driven into only 6 Ohms, which works out to be about 80 WPC into 8 Ohms. I think it is the manufacturers way of inflating their specs to the consumer.