Garmin Connect should be able to recognize duplicate activities from two different devices. For example, when I bike, I record on a 965, and a 1030 Plus. If I save both activities on the devices, they both synch to Garmin Connect and give me faulty training metrics. Connect should be smart enough to figure this out. Strava can recognize when I have ridden with another rider. Why can't Garmin recognize when I have ridden with myself?