Shotscope X5. - I had bought a new one that I had trouble getting to work properly it was just a bit wonky so I returned it. Later on I decided to give it another try and bought another, I took the time to really learn how to use it and now it works near perfectly every time. I switched away from Arccos due to yearly fees and 18 birdies due to the shot scope watch being such an easy and convenient platform.