I can't say there was a difference either way. This grow can't be compared to the LED grows because of methods used and height of plants. Having grown these too tall, the HPS was needed for depth. Being the plants are so wide, the LED couldn't cover the area solo. Even attempting to make a comparison wouldn't be fair.
I am sure however, based on my experience, if I had LED coverage with the proper area of square footage and kept the plants at a proper height, my GS 600w Pro Bloom would have produced well and been a good comparison.
Presently, my thoughts on the 600w Pro Bloom and my type of growing, are that I have an odd size that 3 lights would overkill a 4x4 area, 2 lights would leave the outer most ends less covered, but would still be a good grow. It isn't a fault of the lights. It's based on my area, growing style, yield needs (which determines my style of growing) that determines how to best cover the area. I would love to add more GS led's and would in a heartbeat if the $$ was in the cards. Unfortunately, at present, the initial outlay isnt there.
I am currently using a bigger hood in a bigger tent (5x5) as it covers the area well. I may at some point put this 600w LED and the 400w HPS back into use with my now unused 4x4 tent for good coverage. But again, that isnt to compare, that's just to cover the area.
In an ideal world I'd have a 5x8 tent with 6 plants and 5x600 watt pro blooms or if GS gets them out 3x900 watt pro bloom if they were the right size.