Hi, I made very good results with 3W LaserLEDs of the OSRAM company. Those are the best alternatives for COB LED's, and even better, because you can mix the spectrum you need. I wouldn't go with the 2W Single or Strip ones, those have a high tendency to fail early on. OSRAM did update their spectrums a lot of time. I agree with Jake, if you want a really good LED growlight which lasts for a long time without big losses of efficiency, you will need to do the research. I like it, more and more we come closer to what the Sun brings us. But it is much more than just the light, we see, it is basically Information. And this information must be read. We do it subliminally yet.