The adidas miCoach XCell is a good device for those who like even want to go for a jog and want to have this documented their exact route, distance, duration and especially heart rate. The heart rate measurement is relatively accurate in my opinion and the possibility for a placement test on heart rate basis to complete specific training plans for different goals makes me happy. Even the built-in GPS features relatively accurately on your distance traveled and shows it to you then online in micoach portal. Also Playing sports like tennis (in my case) can be recorded with the device, I have also found relatively interesting. The unit had worked absolutely perfectly with me until now.