a lot of people on this forum will bust your chops for trying out another form of lighting because they think you should be using exactly what they're using. Why? Because they have the best setup, of course. Arguments nonetheless on behalf of led experimentation abound, and they have budded plants out on other forums, namely
Cogi's LED experiment - Reefer World
These lights are more efficient, the problems are only with wavelength. Everyone brags about HID inefficiency when babbling on about lumens. Lumens are important, but to what end? Driving photosynthesis and other plant processes. So much light is wasted and reflected from the plants with HID's that you're really only operating 100W of light anyways (as it only has 25% efficiency) and the plants use only a small portion of the actual light output. So people like to forget that they're paying for four times more electricity than they need to grow the same crop because they're crop turns out so well and there's a big number on the box that says it puts off lots of lumens. It would be like rating an engine to 500 horsepower and driving a honda civic. Better to start off on our end, with 90% efficiency, then at 25%. It works, but it'll never change unless some people say that with new technology that number is no longer acceptable. It will, after all, be someone experimenting with pot growing that will develop a light harnessing these technologies that becomes rich. All the critics will be wishing they had researched and defended their case with evidence instead of spewing off reasons why you're an asshole for trying something different. Led's are a good start. Just accept the fact that you're experimenting. But that should make it all the more satisfying if you can make it work.
good luck in whatever you choose, and research led grows on other forums. You won't find as much info here as the environment is not ready for it...