Usage

GPS is an aid to navigation - don’t ever rely on GPS as your sole location reference.

you might drop your GPS receiver or it might get wet, destroying it
your GPS might run out of batteries
GPS signals might be weak in your location (eg. jungle)
GPS signals can be jammed
the US government might turn GPS off
relying too much on GPS might reduce your situational awareness

If you are going to navigate in remote areas you need to:

know how to navigate conventionally (map, compass, celestial navigation etc)
carry a good map and compass
have a backup plan

If you have the above, then feel free to use MilGPS to augment your navigation.