I am running 3 AI's on a 90gal (48") and am having a hard time getting some of my zoas to acclimate to the LED. I have played with the intensity between 20% up to 45% on all colors. I came from a 2x 250w mh fixture which was also too much light for most of the zoas but at least it looked "bright". Now, I am frying corals (or trying to recover from it anyway) at visibly much less light, but I believe there is so much more blue there that our eyes just don't recognize. I am currently running whites at 45%, but blues at 20% and RB at 15%. The colors don't pop as much as I want but it at least looks brighter and isn't burning anything.
I honestly think that the best overall light for zoas (in my opinion of course) would be a lower intensity MH with LED actinic supplementation. The color of LED fixtures are AMAZING when you play with the lights and have the intensity where you want, but the spectrum put out by them appears to have massive frying capability when the intensity is turned up enough to appeal to my eyes.