As long as new generations of LED's are evolving, a comparison will need to be made. Further, comparisons will need to be made when users get to a point where they can state that they have not changed settings for a protracted period of time. We just don't have enough longer term experience under stable, base-line conditions to make an accurate statement.
From experience, I can say what I have encountered. I started my identical 220 gallon tanks off with 5 AI Sol Blu units over each. I had moderate growth on most pieces and slower on others. My colors though were great. I swapped out two of the units for 250 watt DE MH using xm 20k bulbs in Lumen Max 3 pendants on Lumatek adjustable ballasts. The ballast setting was on the "boosted" 250 watt setting. I swapped out the units because I was afraid, from what I had been reading here, that I was not providing the complete spectrum and that was what was impeding the growth. Plus, with only white and blue/royal blue, it kind of made sense. That was one of the worse things I have done.
My Pocillopora and Birdnest pieces actually lost quite a bit of their color intensity, but exploded in growth. I am not a big frag person and I believed the color would return after a period of light adjustment. I was wrong and should have aggressively fragged. The stuff took over my tank. Both species had little babies all over the tank, on my overflow, glass and powerheads. They then died off at the bases due to lack of light/flow. This led to an algae bloom and getting HA out of Seriatopora is a losing battle. The Sol Blu units were at 55% across the board.
Visually, the tanks looked no different. It was amazing as I could stand in our kitchen and look at both tanks when one had been converted to the LED/MH combination and one had not. My wife could not tell them apart. One way to tell though was to look at the tank temps, one was 4-5 degrees warmer than the other. The living room became hotter as well which was made quite noticeable when the second tank was converted.
I ended up basically restarting the tanks a few months ago, taking out the MH to go back to all LED's and converting three out of the five units over each tank to Hydras. One tank has LPS and softies and is doing great. The other tank is SPS only and, at this point, I have no issues. I put quite a few pieces from Copps in the tank at the end of October and quite a few more mid-November from others. A couple frags from Copps have grown 1/4-1/2" nubs where they had been broken during shipping. Certain frags in the mid-November batch have shown surprising growth in less than 1 month, encrusting their plugs mainly, but in one case where the frag was laying on the rock, encrusting the rock to make a disk about the size of a quarter.
Time will tell, but as of right now, given my priorities, these units are serving me well. I have less heat. My corals are coloring up and growing. We'll see how my batch from Battle Corals/Adam does when I receive them after Christmas.
