So it looks like in terms of cost, LED is now to the point where it is the smart buy if you consider your time valuable at all (how much time do you want to spend changing light bulbs?). The energy expenditure might be the same between CFL and LED, but if you figure you need to change a CFL 3x as often, that's 3 times the lightbulb changing events.

Also, it seems like we are reaching diminishing returns outside of potential manufacturing efficiencies at some point in the future. How far can we go to make lighting efficient until it makes more sense to focus on other areas of energy consumption like the systems that manage your lighting or other home/office utility infrastructure like the Nest thermostat?