I have my 18" and 36" Ray-2 fixtures installed.
I absolutely love the 18" unit. It is perfect for my 20T and looks great.
The 36" one was DOA (it is basically a pair of the 18" boards in a 36" housing - only one half would light up). The vendor (AquaVibrant) worked with me on getting me a replacement in time for Christmas and they even refunded my postage for returning the dead unit to them, so they get high marks for customer service.
The 36" unit also works well, but is not a significant improvement (visually - plants have yet to state a preference) over the 96W PC it replaced. I guess I was expecting it to be a little brighter than the 96W, but as long as plants grow, I will be happy saving $ on my electric bill & lightbulbs.