Ok what would convince the non believers that a good LED is as good as MH, what exactly are you looking for that has not been shown here? Growth has been shown, colour has been shown, the need to not require a chiller in most cases, lack of bulb replacement, amazing dimming, and on and on and on.
So maybe my fellow towny above

has hit the nail on the head, maybe to the non believer the real issue is understanding the complexity of programming an LED to give the right results, OK maybe there is a marketing idea coming to me here, a preset LED, bit like a preset MH bulb? Only thing you do is program your dimming curves. Maybe add some rolling clouds.
Maybe the above comment is the key to this whole debate?
I no longer see an argument in switching back to T5 or MH because the LED lamp did not grow corals or produce colours or worse kill corals, that argument simply falls into the catagory of badly designed choice of lamp and takes me back to a previous long post
So if an LED with a credible track record was sold with a preset that was proven to work, would you buy it?