ive got a sun system 150w hps. its good for flowering clones or for moms. i've used it for flower before and pulled good numbers, but to me it wasnt worth it. dont regret it, but wouldnt buy again
HPS is more efficient at higher wattages.
600-1000 watt hps is a lot more efficient than 150 watt.
Even 250 watt is a step up in efficiency compared to 150.