All is not a rosey as your would think with LEDs. Read the series of reports published by the Caliper Program at:
http://www1.eere.energy.gov/buildings/ssl/caliper.html
Unfortunately this new technology is getting better, but unscrupulous vendors are still making claims beyond reality. Buyer beware. Get a sample to test before you try to design with it.
Also note, high intensity Blue light (from LEDs, or elsewhere) can casue damage to your eyesight. Blue is one of the primary LED colors in high brightness tri-color sources, and looking directly into them (like LED stage lights) can be hazardous. There are also UV LEDs now available, so just because it's an LED doesn't necessarily make it safe.
Cool to the touch may be questionable, as the junction temperature in an LED must be kept cool to give it long life. High Brightness LEDs, therefore, must shed heat via a heatsink at the rear to stay alive. This is one of the primary reasons converting incandescent fixtures to LEDs is such a challenge - we have engineered standard lamp sockets so that they don't conduct heat away from the lamp base. Erich Friend
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