I might be late with this but I just discovered the usefulness of strava's heatmap option.
It uses the popularity of routes, where people have previously gone, and overlays them on the map. You can choose between cycling and running modes to get an idea of trails. Some appear only in the running mode and not in the cycling mode, indicating that they are probably footpads / have some grassy sections.
Here's an example of a Jagungal loop which appears when the running mode is selected. http://labs.strava.com/heatmap/#13/-211 ... 8/gray/run
For popular mountains like this, it means you can search for it, turn on heat maps and get an idea of popular approaches in less than 30 seconds. A bushwalking version like this would be even better since the majority of trails / footpads that we use aren't known in these route building websites.