Google Earth Pros:
1) No ads.
2) Route management. You can store your routes in a hierarchical system of folders and sub-folders just like you store your files on your computer. And your routes are stored on your computer, not someone else's server.
3) Ability to display multiple routes at the same time, with checkboxes to turn them on/off.
4) Because it is an application on your computer rather than a web application, there is instantaneous and continuous response to mouse actions.
Google Earth cons:
1) No direct way to share routes if the other person doesn't use GE. My solution for this is to take a screen shot of the map and send the RD the picture. There is a way to share an interactive map that requires more than one step, but I usually don't bother with it.
2) No map view, only satellite. Not sure why they don't provide this.
3) As Duane mentions, no automatic splits created.