High-efficiency speakers and high-power amps?

I've been wondering what's up with single-driver, high-efficiency speakers, but my current rig is quite the opposite: low-efficiency speakers with high-power amps. Is there any reason why I couldn't -- or shouldn't -- try out a pair of high-efficiency, single-driver speakers, without buying a new amp, just to see what I think? If I were to plug in a pair of, say, Omegas or Zu speakers, would I get a sense of what all the fuss is about by simply keeping the volume turned down low, or would I be missing something unless I were running little 6.7-watt tube amps, or some such?

Thanks.

-- Howard