Working as drumtech for several metal bands, I often find myself in situations where drummers have a clear idea of how they want their kits to sound, so this tool is needed. I also work for a production with rock band and full orchestra, so sometimes the place is loud and I don't have much chances to tune as I'd like. Again, this thing is super useful. I wouldn't trust it 100%, but I'd say it's a good starting point before fine tuning (depending on the venues-halls-arenas). I also work as session drummer, this thing is very useful in the studio!! I find my tuning before the session, and check them while recording. AWESOME.