I just received a Mars Hydro SP-150 and decided to replace my viparspectra 300w with this light. All I can say is wow!!! What a kick ass little light. Blows my other light out of the water. Same watts except SP is fanless, runs 3 degrees cooler, 10x the penetration, better light spectrum, and better light spread. My regret is not getting this light sooner. This grow is a mini test cuz I have no room for another grow and these ladies are my youngest. I will be doing alot more complete grows with this light from seed to harvest.