I have 10 under my hood, and not having any experience with any other form of lighting I like them fine.

I've burned coral and I've starved it for light so it's dependant on what I want to grow.

The only issue I have with mine is that I've got 48" bulbs running from left to right, because of that I'm focussed in certain sections of the tank from back to front. I recently burned a coral because the point where I placed it was directly under my Fiji Coral Stim and Coral Enhance bulbs. I think. I don't really know as the bulbs aren't labled. But only a few corals can live very high in that location.