I recently bought this device noting it was not so much geared to purely fitness regimes, but for activity. It's accelerometer detects movement and converts the activity into Nike fuel points as a generic measure of activity. The more you move the more points you record. As such the more points you accumulate per day means it acts as a reference to how active you are. You can increase the daily target and stretch yourself to meet that goal each day. The idea is good in as much as measurements for calories burned, steps taken etc etc are recorded but the points system provides a general basis for measurement overall. The device is a wonderful gadget, with clear led readout easily read in bright sunlight. As it is worn on your wrist it is not so good for cycling or weight training where a heart rate monitor would be best. Overall a great device that can provide that extra motivation to stay active.
Firmware can be updated as no doubt Nike learns from feedback. It also acts as a watch. Adding the date would be a useful upgrade. The device synchs very well with pc, mac or iOS devices and uploads your data to Nike in order that you can check your progress over the days weeks and months. Well thought through and designed.
I call it a gadget as that's just exactly what it is. It's fun and simple to use and provide, for me at least, great motivation to try and beat the goal I set myself on a daily basis. For me it also works OK whilst cycling, as the jolts and jiggles from on and off road riding seem to also to accumulate fuel points. Is it a life essential, no most certainly not, but if you are like me and love gadgets it's great fun. However all that having been said - it is a lot of money for what it is and a £50 price tag would be more in keeping with it's usefulness and functionality. Nevertheless it made for a great Christmas present from the wife.