As I do not like motion -Based / Garmin Traing Centre I also use SportTracks with my Edge 305.
However there are large discrepancoes inthe values.
The two rarely agree with different values for the milage.
Tonight a ditance of 7.53 miles was downloaded on Garmin, and on SportTracks....... 695 miles.
Re-downloading produced identical results.
Anyone else had similar problems?