I can speak to the issue of efficiency versus durability and reliability from the perspective of an owner of an electrical and mechanical contracting firm. LEDs are probably the best example of a much more efficient, durable and reliable technology replacing a complicated and unreliable "efficient" technology (fluorescent lighting). We'll see the same thing happen with refrigeration: the early generations of "high efficiency" systems were more prone to failures, but as manufacturers gain experience we're starting to see the mature, more efficient systems deliver better reliability than all previous system types. The function curve seems to be an efficiency-durability tradeoff early in the development cycle, and then once the efficient technology has matured, you get better efficiency AND better longevity and durability.