I have LEDs and have just gotten into SPS finally after having them fixed since the drivers were not calibrated properly. As I am just getting in, a friend gave me a few sacrificial frags of ORA joe the coral, ORA red planet, and a few others. Anyways they were some brown frags (except the red planet) because they had been on the undersides of his huge colonies and were also stressed from the move to my tank and my low mag and alk. After I quickly fixed the mag and alk, they are all coloring up. The joe the coral especially went from me not being able to ID it as joe the coral, to wow its green and blue in about 3 days. I think I'm starting to believe!
I have 30 Cree XR-E LEDs over a biocube 29g.