There is one additional benefit to LEDs that I have not heard mentioned anywhere else.

Light leakage.

Now to those who have a sealed room or a light-proof tent, this is a non-issue. However, as I have a small closet grow, it is a big concern for me. I cannot light seal because of ventilation issues.

Most of the light from the LEDS is not optimized for human viewing, but for plants, so right there is a big savings. Also because LEDs are so directional, the light does not bounce all over like with fluoro or HID.

If I were to quantify, from outside the closet I would say the light leakage is reduced 80-90% over my CFLs.