"Hit them when their down", some fighters would advise. And Fitbit is definitely down, or is at least going there. Its earnings report is less than encouraging and rumors are swirling about delays in its smartwatch renaissance. And while all this is happening, Garmin comes out with the vivosmart 3. The latest in its line of smart activity trackers packs almost everything and anything that you need to stay fit and healthy, but, most importantly, with a price tag that could spell trouble for Fitbit.