Strengths: Fairly cheap, Easy to use, small a v lightweight, superb website and online community, easy to monitor progres and set person goals.
Weaknesses: Whilst you need t download the driver for the 'usb stick' you do nto download the full softwear so you always need to connect to the net to see your progress. Also there is some room for improvement with future models maybe having heart rate monitor and a light so you can read it at night / low light.
Overall: This has honestly exceeded my expectations. It is a real motivator and thanks to this I am now pushing out 14 mile runs as my long Sunday run so I cannot really complain! I do have a gut feeling there will be aversion two in time but at £40 I was happy to buy this now. My one top tip - join the Nike + forum first, see if you like the feel for the web site as that gives a very good indication of how the sport band works.