The website gives a comprehensive display of your workouts allowing you also to rank them by distance, speed etc. You are able to plot speed, altitude, and heart rate against your track. I've found the tracking and distance to be very accurate. Altitude is not so accurate but that is a function of the way the GPS system calculates position and not a reflection on Sports tracker or the GPS unit.
I regularly run it in off line mode to extend battery life especially when I'm in poor cell coverage areas.