Rob - right now I just have LPS, leathers, zoas, mushrooms. The only SPS I have left (after adding the angel) is a green Pocillopora growing on the back wall under the gate. It was from a nice Pocillora I had that evidently spawned some eggs that took hold there. For some reason the Flame Angel didn't touch that one. I started, and am still at, 40% on the 2 Blue LEDs, and 30% on the whites. So far all is good. If anything looks stressed I'll back them down. I think with all 70 degree optics that's also helping spread out the intensity. The Sols ship with 40 degree optics in the center 4 LED pucks, and 70 degree on the outer 4 pucks. Knowing that I'd be mounting low, I had the replacement 70 degree optics before my Sol order even shipped, and went all 70 degree before putting the fixture on.
angnak - from what I've read elsewhere (if I understood it correctly), I think the LED lighting can be deceiving vs halides and T5 - maybe not visually as bright, but the light energy is still there. Maybe after a while you can increase the intensity or lower the units if that's possible? Are you getting a lot of bleedover on the walls around the tank with them at 18"?
I'm sure no expert on these things, so don't trust anything I say as facts LOL!