SmokeSara, can you please stop posting a dozen pictures of your product in every post? It makes it really annoying to scroll through and has nothing to do with the topic this thread was created to discuss. It's not a question of whether LED's can grow cannabis - we know they can. I'm trying to find a standard to compare the many LED panels. You can't do that honestly through a picture contest that includes so many factors other than the light. Let's focus on the data.
In the PAR chart you posted of the Epistar320, the average PPFD of the 8 data points on the 4x4 box is 175umol. Based on the study that was posted on pg 2, 175umol yields approximately 25% of cannabis' maximum photosynthetic rate. The difference between a 3x3 and 4x4 foot space is 7 square feet. That 7 extra square feet is worth 44% of the total 4x4 footprint.
4x4 box is avg. 175umol, ~25% photosynthetic rate. (44% of the total footprint)
3x3 box is avg. 332umol, ~50% photosynthetic rate. (31% of the total footprint)
2x2 box is avg. 772umol, ~80% photosynthetic rate. (19% of the total footprint)
1x1 box is avg. 1455umol, 1499umol if you count the center reading; ~100% photosynthetic rate. (6% of the total footprint)
The center 1x1 is nearly perfectly at the maximum photosynthetic level. If that was the engineer's target they did a great job. But when is it acceptable for the marketing to stretch that achievement into claims of 3x3 and 4x4 coverages? I personally wouldn't be happy with 75% of my space in a 4x4 producing at less than 50% of the maximum rate. I imagine it also makes watering and co2 injecting more complicated when half of the 4x4 area is photosynthesizing at 25% the rate of the center.
For flowering cannabis you want at least 700umol, so the epistar320 would optimally be used in a 2x2.