It is hard to tell What is what for me. There are a lot of different company's trying lots of different techniques. None have proven them selves to be the best. Also from my research it seem you yield a true gram per watt. Which is double or more an HID light. All watts used to generate light turn in to heat. That means Led lights will still make half as much heat as an hid bulb minus the ballast inefficiency. None of them are prepped for air cooling and that is a reality that they are going to have to face at some point in time. They are also not sold in a lot of shops so a warranty issue could cost you a whole grow cycle.