Well, if you set aside the possibility of photoinhibiting your corals (or, opposite-- under-lighting them), then you really don't need to fret the long-term viability of LEDs for SPS. The main problem I've seen is folks using them too brightly--- while others say they've seen people not using enough (I have to admit I've very, very rarely seen folks underlight a tank with Cree/Rebel LEDs). That's an easy fix, just dim them down. If it's not bright enough, toss in a few more. (sorry but I can only really discuss the DIY aspect of it, I don't spend my cash on premanufactured arrays lol) I think that really just leaves spectrum as the only real issue with LEDs, and the spectral analysis thread linked earlier in this forum shows that the right LEDs (of which there are many, many) are just as good as halides, when used in the common cool white or neutral white configurations------- except for the lack of spectral intensity at narrower wavelengths like 400-420nm (violet), which many halides do greatly.