Strengths: Box on the arm much smaller than old model very unobtrusive. Fantastic for marathon training to get a better idea of long runs, distance wise. Like the Lap/split facility to see when you start to tire on your long runs. It is a nice looking watch as well which is not too big which means you can wear it in the bar after training and it does not stick out. Very easy to set up even for the less technical of us, the instructions were easy to follow. I like the idea of having a distance and speed facility with the heart rate facility.
Weaknesses: If you catch the box just the slightest knock and it seems to go off line, and if you make a mistake and switch the watch on without swithing the box on it takes a while to reset but this is just a minor thing. It has a clip to wear on your hip as well but the performance is very hit and miss with it here.
Overall: A good value for money product which can be used for different sports, i use mine for running, walking and cycling. First time i have used a GPS system and i have no quibbles.