Several years ago I did not use LED because I think the technology is not adequate yet. Blue and white light just not enought to let the coral keep their color. The manufactors found this out after the early attempts. Now everybody know that broad spectrum is needed even when our eyes cannot tell the different. I have to admit that LED is still expensive. This is the nature of our hobby. More people produced them and the price will go down. Anybody remember a MH bulb for 120 and need to be change every year?
There is no question that a good LED fixture can produce the growth and color that is just as good or even better than MH. I know because I am doing it. Today light for a reef tank should not be a problem especially if you have money to burn. The future of reef lighting is LED. Ther is no disadvantage that cannot be solve with tweeking the placement and spectrum of the lighting elements. The advantages of LED are too much for MH and Florescent technology to overcome. In fact, barring new technology, the future of all lighting for all applications is LED