Is it noticeable the difference?

Hi everyone. Im currently using a 1.2mx1.2m tent, growing 3 strains using a spiderfarmer 2000w. Having excellent explosive growth despite the tent being bigger than its suitable for, but as such, im looking at bigger lights. Was interested in the 4000w version but its got ridiculously expensive for some reason. So I've looked at sylstar. Massive difference in price, and seemingly very similar ppfd range, par range and power as spiderfarmer using same leds, just a lot cheaper.
Would people recommend a 450w from the wall one, that does cover maximum 1.2m tent, or go for the 600w from wall one, that covers 2mx2m? Also anyone know much about them?
Thanks

I used to get at least an lb every 9 weeks with a 400w HPS in a 1.2x1.2 tent