Strengths: The Polar s625X is an excellent bit of kit. It feels well made & will take some real punishment. The pod is extremely accurate and again robust & weather-proof. The computer software & ease of transfer is second to none. Not only a heart rate monitor the watch is also capable of interval training exercise sets which can be distance or exertion calibrated. There are over traing & fitness level tests.
Weaknesses: Little to report here, the altitude measurement needs to be set each time it's used, which renders it pretty useless. An ETA calculation for various race lengths would be nice. The battery compartment on the pod is quite fiddly to access. When using the interval training feature the auto lap feature must be turned off manually or your feedback becomes ruined by the lap times. That apart & maybe the initial enormity of the functions the pros far outweigh the cons.
Overall: The s625X by polar, has revolutionized & invigorated my running beyond compare. Most notably, my training has diversified to include interval training, heart rate exertion exercises & calculated lap times whilst out on the road, rather than on a track. I am now able to expand my, once routine, measured running routes to include bike rides with the kids & also bridal way routes with my wife on horseback, whilst still being in control of my weekly running schedule. Once back home, I am able to download myriad pieces of information onto the computer to dissect & muse over. I have discovered ways to increase speed whilst reducing heart rate by analysis of exercise sessions on the PC. Reducing stride length & running economically with an upright stance has led to dramatic improvements in my PB’s. This progress, I have been able to monitor using Polars excellent software, which is included with the product.
The measuring pod itself is extremely robust, weather proof & lightweight, you don’t realize it’s on your shoe. It is easy to transfer from shoe to shoe, however the changing of the AAA battery every 150 miles or so is a bit fiddly. The accuracy of the pod in measuring distance is unerring. I completed my local 10K fun run with my watch reading 6.20 miles; you can’t get much more accurate than that. I do find however that the slower the pace, the less accurate the watch gets, maybe 10 strides difference in a mile, still far more exact than the old map & string routine!
I purchased the watch when it first appeared on the sceene and therefore paid a premium. The watch is now very reasonablly priced & I have no quarms in recommending it highly.
The Polar s625X has kept me motivated, keeping to my running schedule, & has improved my technique & times, what more could you ask from a watch.