I have been working with LED's for thirty years now, I can remember the first blue LED's. They were about 80 USD each (direct from CREE, silicon carbide substrate, as opposed to the sapphire substrate now used) and ran on 3.5 volts at 20 milliamps, and when you turned it on it looked like someone painted it blue. A lot of progress has been made over the years, but they still have the same drawbacks as always. LED's are very wavelength specific, they put out one color and nothing else. THERE IS NO SUCH THING AS A WHITE LED. What you see as white LED's is nothing more than a blue LED with a bit of phosphor on the DIE to re-fluoresce the blue into other colors. This is not the strong point of LED's, which is to create one specific wavelength. In my opinion LED's should not be used alone, but in conjunction with other light sources, to amplify the beneficial aspects of the lighting being used.
One more tidbit of information, many people see the large heat sink on LED lights as an energy waster. This is not the case. The most efficient light only converts about 25 % of the electricity into usable light! The rest is converted into HEAT, a not avoidable fact. Another not avoidable fact is LED's hate, Hate, HATE heat. They must be kept very cool. I cannot stress this enough. Most LED's coming out of China are overrated and running way TO HOT. Just a few degrees can make the difference between 50,000 hrs and 2,000 hours.
All in all, LED's can boost an existing lighting system in a wavelength specific way that no other source can, extremely efficiently. But if you have a choice, point your fan so that it hits the LED light just to cool it a little more.
