I've got three amz "quantum" knock offs, a dozen QB288, two dozen QB132, the four Rspec FR and a sunboard 96x9 strip build & I believe the quality of the flowers is considerably better with the higher density LED count per square foot.
The 12-288's are in one space and after I recalculate the weight of all the heatsinks I'm going to hang the 272's on the end frames. It's a pretty hefty amount of aluminum and I've already designed end caps for ½" conduit if I feel I'm pushing 50% of the recommended chiminilly willy weight limit.
I'll make trusses if needed.
It makes no sense to trash expensive lights trusting a chiminilly made tent with peanut butter welds on tin foil pipes!
The center rails look like a good place to mount those Rspec FR which I got the Slate 2 double, whereas the other sinks are Slate 2 single.
Slate 2 singles are longer than the double - but I'm not driving them hard like many are and the lower power handling isn't a biggie.
Anyway, 142 decent LEDs per square foot is going to give better coverage and higher PPFD than the 4*8 next to the other with only 99 LEDs per square foot.
LM301's are a decent diode but if they're not actually Samsung they're not going to deliver what's been "promised".
I believe the SF4k was advertised at something like 3 (or more) umol compared to 2.47 umol for the Rspec FR.
The Diablo based boards are NO JOKE and will far exceed anything else you may have already had and I believe
@curious2garden has a few Diablo X fixtures that have some righteous numbers for comparison...
Once you have some miles on both and you can A-B, compare - we'd love to hear from you here - posting your experiences!
I don't think you'll be disappointed with either and I - myself would probably never use CO² to utilize the extra photosynthesis abilities.