Originally Posted by
Steve B.
When I had an Edge 1000 I ended up buying the Garmin Topo series as I was unable to download the topo version of OSM. I desired topo for gravel riding in Vermont and upstate NY. I was subsequently unable to load those Garmin topo maps to my 1030 but then discovered that you can enable topo features on the installed base map on the 1030, so problem solved. I had to download and install OSM maps on my 810 way back as it only came with a very non detailed base map. I used the DC method to get the OSM maps, this was many years ago.
Topo maps can be an exception (especially for hiking). I find the topo lines useful too.
The 800/810 didn't come with ("real") maps. You could get the "Garmin City Navigator" (CN) maps extra or in a bundle (but these had the "you have to pay for updates" problem). The CN maps were the standard maps Garmin produced for automobiles. Or you could (as you did), download OSM maps.
The "non detailed basemap" comes with every Garmin (even the new ones). The purpose of it is to make rendering (displaying stuff on the screen) faster at very low zoom levels and to provide some sort of context for regions you don't have detailed maps for.
The current Edges come with maps based on OSM. You get updates for any regions you are entitled to. With the 1030+ and newer, you are entitled to world-wide maps. With earlier models, you were only entitled to a "home region" for the device.
There's less and less need for alternative sources for OSM maps but people can still prefer the look of different maps. The alternative sources don't generally (?) have topo lines (you can get overlay maps that provide them).
That one can create and use custom maps for the Garmins is a cool feature (even if not everybody cares). That wasn't by design on Garmin's part: people reverse engineered the format.