I use the Zumo import feature to creat a route from tracks. On the street it does a nice job of converting. Good to clean the tracks first anyways though!
A 7500 track point conversion. Original Tracks
If you are off road the conversion can be an issue especially when you are very close to a street that is in the mapset. Also when off road you can bump into the limits of how many points an off road route will accept.
Sure can load it back to Mapsource to fool with it (route and tracks).
Downloading the tracks is really helpful when you are following somebody on a new ride. What the Hell did we do???? You can clean the tracks to get rid of stops/missed turns etc and then up load to the Zumo to get a new route for a return engagement by yourself.