I have posted the tremendous potential of LED tons of times in this blog. It is 7-8 times more efficient, lasts 20 times longer and emits almost zero heat (incandescent heats to 300 degrees).
Since there are almost no standards in the lighting industry, there are issues with inferior LED bulbs, especially with poor color rendering.
Still when its good...its really good. Have a look at the new Kowa desk lamp.
It uses all of 4.5 watts...