This is an interesting thread.
I'm running a Gen 1 Radion over my Elos Midi. The tank consists of softies, and I'm perfectly happy with the light. However, I'm in the process of retooling my reef (equipment, large basement sump, adjusting my husbandry, corals, not being lazy, etc) and would like to finally go SPS dominant. Most of the research I've done agrees with Rich... Well done, colorful, SPS dominant, LED run tanks are the rare exception.
Here are my thoughts (and I'm probably wrong on some if not most points
) --
First, LED rigs with wider optics (or none at all) seem to work better. They blend the individual LED colors better, and create fewer hot spots (that dreaded disco ball effect). I think the hot spots are worse for colonies rather than frags, as there will be more dead and hot spots reaching each coral, effecting each colony negatively. With T5 or MH, the area of light is much more consistent and this doesn't seem to happen as often.
Second, and this one is probably more user-specific, but I think LEDs are much more difficult to dial in correctly for two main reasons; they don't look as bright as conventional lighting, even at higher intensities (and the variation can be difficult to view), and there are so many fixtures, revisions, optic choices, etc, that it's not plug and play. If you want to light your tank with a 400 watt Radium on a Lumenbrite pendant with xyz ballast, it's going to be pretty easy to get reliable recommendations. Try that with LEDs.. it's extremely difficult.
Finally, I do feel that people in general don't give LED's enough time. Their corals are subjected to a huge change, often react poorly, and the user will immediately blame the light rather than the change. We used to see this same thing when T5's hit the scene, and tons of people said they wouldn't grow SPS corals.