Its no longer a question of whether they work or not. The only thing left is price. Indica 44 has posted some useful sites for information and purchase of led's. He posted them towards the end of My Current Setup: Journal??
The 14 watt light that HomeGrownLights sells gets tested in the last link he posted, I think its on page 16, so you don't have to read the whole journal. Other information that I found indicates you need 25 watts of led's to replace 100watts of hid's. So to replace a 600 watt hid light you would need 11, I say 12 because I'm a balanced kinda guy. 168watt. Set up in a 3' x 4' grid it will cover my tables very nicely. These units are shown covering one sqft. with the light centered (duh) over the plant. I'm thinking you could make a frame for them out of pvc, lightweight, sturdy. No heat issues, just good air movement. Same lights the entire grow. Ryan, the companies owner responded quickly to me e-mail's, I received two answers from him in one day, that's impressive, makes you think he care's about his business. No rash claims, lets others do the research and has made improvments in his product from the 9 watt to the 14watt.
The panels are not quite 5" sq. which should make it easy to build a grid, one measurement will be ditto'd. I will have to wait until I get back from vacation to buy the lights, I am going to check out some pvc for a frame for them. If you do contact them, at least mention where you got the information that lead you to him. If we can get them priced at $50./ panel assembled or less it just makes sense to me. So simple, wanna grow a plant, you need one light, three plants, three lights, add as you grow. Have a 4' by 4' table, you need a 4' by 4' grid. Using these lights instead of what I have now should save about $50.00 a month @ .10/ kilowatt hour. VV