I was in the same situation; ready for a new light after recognizing my light was inadequate. Obviously any of the Mars , Spiderfarm 600w lights will work well in a 4x4, but I wanted to see what I could get for less money. I started looking at COB Cree lights and finally settled on a Philzon 2500 COB light . It has a ridiculous PPFD at 24 “ and will do nicely for a 3x3 flowering area. They have a 600 watt option as well but I had a 200w LED and decided I would used the 200w light at the rear of the tent and the COB at the front . I just finished a grow and had cleaned the tent for the next grow when the new light arrived. I repositioned the lights and turned them on just to see how bright they were and I believe this lighting scenario is going to work well. The Philzon 2500 ( why it’s called this is beyond me) has 446 watts from the wall. I found one on everyone’s favorite auction site for almost $100 less than Amazon wanted . It has over a thousand reviews with nearly all of them favorable . Two year warranty. I know the detractors will say ‘ sure the PPFD is high but the drop off after the first two feet in all directions is significant .’ In other words, coverage is deep but not broad. The opposite can be said about traditional LEDs; the coverage is broad but not deep. I’m hoping with the mix of both lights I have addressed each limitation and together they will yield the lighting four or five photoperiod plants need.