I have the Polar 725I and love it. You can download data to your computer and track your training. It is set up to show tome in HR Zones. If you get the Polar get the cadence sensor because you can do training by Cadence. The software has reports and graphs built in that are easy to modify. The watch also has lap funtion for recording intervals. I use it for hill work and spin workouts. Also the 725I has an altitude function so you know how much you climb. Another thing I like is that you can set up different exercises in addition to cycling. I use it for running and I have a seperate exercise for indoor training. I hope this is helpful.