I have one and I really like it. I'm a hybrid user, so I still have "old" tech with LEDs. I just replaced my halide bulbs and I was able to check the old bulbs before replacing with new ones. I like that you can calculate DLI, get spectrum charts, etc...for me it's a nice piece of gear that's going to make switching bulbs and checking my LEDs spectrum much easier. I think it can be useful in many ways, but it's not for everyone.