I got a Nike sensor and sportsband as a Xmas present from my husband. I have been craving one for years, ever since my co-worker got one from her husband and told me about it. This was before it was even available in Sweden I think (the co-workers husband bought it in the US). And before smartphones and gps-based running apps. Now of course there is a Nike gps app and all sorts of Nike gear combinations, but if you don't own an iphone or a modern ipod the sensor and sportband is the easiest option to go for if you want a Nike setup. It's basically a more advanced pedometer. It keeps track of distances, time, pace and also gives an estimate of calories burned (I don't trust that sort of measurements though, from what I understand gadgets tend to overestimate that number by a lot).
The biggest advantage with a sensor/sportsband over gps is that it keeps track of treadmills runs too. The biggest disadvantage is that there are no route maps and the distance can be slightly off (it can be calibrated though). Compared to the free Runkeeper site the Nike plus is nicer, more visually inspiring and has better organisation. Though when I tried to upload runs and walks during the holidays the whole Nike running site was pretty much collapsed due to overload. I had numerous of issues and spent a large chunk of time on their Facebook help forum and it took several days before all my problems were sorted out.
Today I went for a run again and this time everything worked perfectly. Except my time, lol. I was actually faster two weeks ago. I blame it on the cold. This was the first time ever that I ran outside when the temperature was below zero. I haven't been running at all this fall but I am planning for a 5k in the spring and a 10k in the summer. Since I got the sensor I've already been out running three times, so clearly it was a much needed encouragement!