I just wanted to do an update in case anyone comes across this thread in the future. I added two radion G4 xr15 pro's to my 4 Kessil A360s on my 6 foot tank. I have them spaced as Kessil, radion, Kessil, Kessil radion, and Kessil. Here are my observations. I run my lights fairly high off the water, so the spread on the xr15s covers most of the tank where I have them placed. I run the AB+ program, which is close to the color blend I was at on my kessils. Thus, I believe the color blends pretty well between the different units and is not a concern (or I know I could adjust my color on either units to get the color very similar). The radion shimmer does have noticeably more disco ball than the kessils. I think the kessils make it less noticeable, but if you're very sensitive to color separation, this might be an issue. I run 4 bulbs of t5 also, so the color separation and shimmer gets muted greatly when my t5s are on anyway. Overall, I have been pleased. The radion xr15s are more powerful than my Kessil a360s from a par standpoint (comparing one unit to one unit), and I have enjoyed the controllability through my phone app with the reef link. I run a canopy so the mismatch of units is not an issue from an aesthetic point of view. The mix and match approach has worked well for me, as I have been to keep my older kessil lights and seamlessly add in some newer units that I needed to support my acro lighting needs.