Strengths: This kit has revolutionised my training. I've been using it for over a year and have been impressed with it's reliability. It measures distances very accurately and consistently and provides excellent HR feedback for post run analysis. This can be done even without the additional Datalogger to download to your PC because the watch has a number of summary modes providing data such as ave speed, ave pace, best pace, ave HR, time in a specified HR zone etc. I also love the hands free splits - you can set the watch up to take splits based on distance or time. I have it set up to split each mile and then you can review the aforementioned summary data for each mile of your run.
Weaknesses: The arm unit is a bit bulky but I soon got used to it. Battery life is ok but I invested in some rechargable batteries and just replace the battery every 4 or 5 days which is easy enough to do.
Overall: A great running companion that provides very useful feedback on my performance. I never run without it and have found it accurate and consistent. By looking back over the data on my PC (I also use the Datalogger which I also clip to the arm band) I can see how I have improved over the months. Quite simply I wouldn't be without it.