I have used integrated from Cast and Volt. But mostly I have used retrofits from Illumicare and Brilliance. All these alternatives have worked well for me. (Although, I should say that I am not yet a high-volume business.) The integrated developers like to say they have the answer to longevity and the retrofit developers like to say theirs will last just as long. Despite the laboratory testing, there is no way to know whether one or the other or both or neither will last the purported 12 to 15 years. The debate seems to be centered on isolating the driver from heat and moisture. I notice that the retrofit LEDs apparently think the isolation can be done in a small amount of space i.e. part of the "bulb." The integrated fixtures seem to use a lot of space to achieve what they believe is the necessary isolation resulting in bulky (some say robust) fixtures. Or am I wrong that there are no "small" integrated LED fixtures?