efficient | green | power supplies (Score 1)

A combination of this and the article on building a silent computer got me to thinking about how loud the power supplies are in my computers. As I was digging around, pricing power supplies, though, I started looking at the efficiency ratings (seeing ~70% at max load). Doing a little searching yielded articles saying that efficiency should be between 65% and 85%. Now, it would seem that a more efficient power supply should generate less heat, requiring less airflow (translate that to "fan noise") for cooling. Oh, and it is good for the planet. One web page hinted at tradeoffs between efficiency and stability. Does anyone know of any power supplies that really are in the 80-85% effient range (and are quiet)? (Make/Model, where to find one, etc. would be totally appreciated. Totally.) Or perhaps I expect too much.