The V650 gives you everything the M450 has to offer as well as the OpenStreetMap feature and Route guidance allowing you to see exactly where you are on the map whilst on the go. It also boosts a large 2.8” colour touch screen, it is understandably heavier at 122g to the M450’s 50g, it gives you the same accurate altitude data with the built-in barometric pressure sensor, compatible with the free Polar Flow web service and with the Polar Bluetooth Smart heart rate and cycling sensors.