I got one from Amazon and returned it because it wouldn' charge. I bought a second locally and love it. Definitely a 5 start product but there is a problem. The charging cable won't work with all USB 5v1A chargers. When the watch is charging a small white lighning bolt lights on the watch face followed by a ring of greeen light and the percent charged in the center. My watch won't charge with a UL listed charger that with other cables always charges phones, hearing aids and bluetooth keyboards with never any problems. With this charger no light goes on and it does not charge. I am presently using another !A charger that so far works fine with the charging cable. I believe there is a manufacturing defect in the USB end of the charging cable. I hope Samsung will take a look at this and correct the problem. The watch itself is outstanding. It keeps track of footsteps and time of exercise and provides a plot of heartrate vs time during exercise. It also keeps track of daily heart rate and gives max and min values hourly. You can make your own exercises so I use a rowing machine and since it didn't have that I made my own exercise for that. The calories may not be right but the exercise duration is properly recorded. You can customize your watch faces and there are quite a few available. You can add weather including temp and wind speed to the watch face as well as steps, heartrate and percent charged. You can set goals for steps, exercise duration and calories. In my case the watch uses about 50% of the charge daily so I shut the watch off at night and recharge it every night. In addition to the watch face illuminating with a wrist flick there is also an always on stting you can activate. With care you could probably get two days out of a charge as long as you didn't want to track your sleep which it can also do.