I dont really have anything against leds but they did not work for me on certain types of coral. I am getting more into high end SPS and they are not cutting it. I have had two DIY fixtures and used mostly CREE Leds. My last unit had 44 leds (see the DIY section) and I received great growth on chalices, LPS, zoanthids, etc. but no acropora's, millis and some other highend SPS. I have had milli's & Acro that are 1" for over a year, good color but no growth, hopefully I can get them to grow now with ATI, a proven fixture. Another issue is the Shadowing issue, most of my birdsnests SPS would only look great if you look at them from the top but not from the front (they look brown.
I know people that have leds and do have good success growing high end sps coral but I gave it a try for 4+ years and finally gave up....