I do like them as the HEI optics of the Gen 4 get better spread, but at a cost of the pucks hanging down below the fixture. When you look at the tank the brightness of the HEI optics draws in your eyes from the sides and dilates your eyes when you do glance at them. The Diffuser makes this effect go away and gives the lights a more even spread. The fish still pick up the different color LED, but I do not notice the multi color led separate. I do not notice the disco effect in my 90, but did see it before I put diffusers on the Frag tank on the lighter colored corals. I also like the fact that they protect the pucks from Splashes and the way they mount with new magnetic bottom they go on very trick. Very well made and nice option for Radions. I have not run over 50% yet with these lights as they put out a ton of par!