Jozo-sha,
I am dying to know how these GS panels work out for you as I am sitting on the sidelines right now comparison shopping for a pair of LED panels. There just aren't many references to GS panels on the web, being that it is relatively new, but I still am hopeful that these lights can perform (at least on paper, but who goes by that anyway!). Good luck and I hope to see updates from you!
I will not put my eggs into one basket and say "OMGTHEBESTESTEVAR!!!!111" or anything at this point, but the initial signs in my current grow lead me to believe that GrowGSL's light is going to KATN.