I just saw that too late... but I actually went from a 150W MH (electronic ballast, and Radium bulb) supplemented by 2 Reefbrite strips to the Radion 15wpro and I must say I love it.
The tank looks exactly the same with the setting I use (at 55%, with blues and purple at maximum, other colors a bit less, so I get a very white tank, but with pop).
Growth wise, more or less what I had before, maybe a tiny bit less due to the decrease in temperature from 81 to 79...
The good things? It is using half of the electricity, and my chiller which used to be on 4-5 times a day is now kicking only when the steam pipe radiator decides to turn the place in a sauna.
The bad things? Well the minor reduction in SPS growth I guess... but I do not really care about that since I am not going to open an aquaculture business anytime soon.