Yes, the 600. Was also a monocrop, so it was pretty easy to see what lights performed best. In the same room I had 4x Grower’s Choice 680s, 1x Gavita 1700e, 1x Photontek 600, 1x Vanquish 650W, 1x Phantom Photo-Bio (8 total). The development under the 600 was the worst.
Each light was responsible for a 4x4 FastFit Tray. Not trying to sell other brands, just personal observation. This was my second run with these same exact lights, both times the Photontek was the worst producing (weight, bag appeal, etc.). The controller to dim the light is detached hanging from the unit, so that is a positive thing compared to the others.