I have a problem with the statement: "white LED-based lights are still less efficient than current CFLs", given what I know about LEDs. Talking about equivalent light to tungsten bulbs (the standard) a 40W CFL runs in the 10 watt consumption range, while the LED is 1.5 watts. Now I agree the CFL 40W puts out more light to my eye than does the 40W LED, but not 6 times more light. Also, a more complex power supply: step-down voltage and full wave bridge rectifier would increase the efficiency of the LED light on an A/C circuit. But, this complex power supply will have some of its own losses, will be bulky (by comparison) and will add serious cost. Given the low cost of a full-wave bridge and a resistor, an LED setup that uses enough LED in series to approach 100 volts to light-up full should be very efficient, albeit a fixed brightness. This would be about 25 LEDs which is still not very bright in my experience. I'm not sure if more LEDs adds more spread of light, or more intensity, or both. This suggests for brighter LED fixtures two banks of 25 LEDs, in this example, which has two banks in parallel each has its own rectifier and resistor thereby eliminating the parallel "problem". The two banks are in effect each connected to the A/C source.