I recently discovered that the folder "Favoriten" (german) brims over with useless entries and there seems to be no method to delete the whole content at once. Each time I upload a .gpx file, say a section of the route "Atlantic-Black Sea", hundreds of waypoints pour in the folder "Favoriten" uncontrolled and have to be removed individually. Obviously most way points are not worth saving in this folder. Each deletion needs six steps, spread over the whole display, is therefore error-prone and takes a lot of time. This is inacceptable and idiotic! Does Garmin implement an efficient approach to clean up this mess? By the way, deleting the "Locations.fit" file on the device doesn't work under Windows 7/10 as well as under MacOSX: after startup of the device, it turns out, that the previous file content has survived.
Generally I'd recommend to Garmin to care for the basic functions to work. Today the navigation and training computers are overloaded with useless features. On the other hand, self-evident things like measuring the distance between to points don't work (my device counts up to one third more distance than the old fashioned map) or are so deeply buried in the menu structure that more than fourty years of life experience, a technical university degree and twenty years of software development, system and network administration does not suffice to find the setting. I have accepted that I have burned 400 Euro for nothing, since I have no other choice. But the behavior of the edge 820 is an insult for each of us, able to count to three.