The bulb life is expected to be around 7-10 years, but they really don't know for sure yet. LED's usually have a nice long life. I haven't seen them over zoas, but all the functions are pretty cool (sunrise/set, different spectrums, etc.). After 7 hours of use, you can touch the bulbs and there is no heat. They are pricy, but with savings in bulbs replacements and electrical use, the ROI may not be too bad. They measured par at our frag swap and they were decent, but don't compare to my 250W DE 14K Phoenix's (seems like the Solaris varied from ~400-700 photosynthetic photon flux, depending on a number of things) The par meters change readings dramatically depending on distance from light just through air, which I thought was interesting since air isn't a medium that dramtically reduces light. They drop alot more once you go underwater (expected that).