I have had one for just a couple of weeks.
Personally, I don't find it particularly useful for fitness tracking, because it measures steps. My workouts consist primarily of Megaformer and spin, so the watch isn't useful for tracking. I do sometimes checkout my heart rate during spin - if I were really concerned about accuracy, I would wear a chestband. But if you are a walker or runner, it would probably be quite useful.
I do really like some features I didn't think I would at all care about, though. I don't miss texts and phone calls because my phone is in my purse or on the charging station. Also, I get calendar reminders and notices about how long it will take me to drive somewhere I have an appointment under current driving conditions. Plus, I somewhat prefer the look to my previous tracker which did not have changeable bands.
And it is better than my previous fitness tracker in one respect. That one used to buzz and tell me I needed to move - while I literally was dripping sweat onto the Megaformer. THAT was annoying!
