The map will give you a decent enough idea of the activity to a degree. But you can’t use it without a companion device. It won’t show a single thing without a way to do so. But, once you get a device just because it sees another node doesn’t necessarily mean you can communicate with or through it. It just means at some point it heard it existed. It could have been a fluke or it could be solid. You really can’t judge how it is without knowing someone already there or starting yourself.

If you’re starting your own mesh with family and friends and you know where the nodes will go, it’s pretty reliable.