I use these websites openfietsmap, freizeitkarte-osm to download my maps.
You can download many different countries from both these sites at the same time. It can be anywhere from 4 GB to 6 GB and any one time.
We are talking 3 or 4 countries form each website.
Plus I can go to different websites and Forums and all of this takes 1 1/2 hours to 2 hours to download all this data I think the longest took me 3 hours because I had a backup of my computer start.
Reason why is all of this maps are compressed in EXE files or ZIP files.
When you download from Garmin you get one file then another and then another at a time all in your temp directory.
Then it takes all the files and puts then into an install package before it even installs the map update.
You are connected with Garmin Express the whole time.
So this goes on and on for over 5 to 6 hours.
You can not disconnect while this is going on.
Rather than making one EXE file that a user can download and install on his computer and Nuvi.
This way you do not have to stay connected to Garmin the whole time. which is a total waste of time for any users.
So it is not my Internet provider that is slow it is the way you have to download Map updates from Garmin.
Make it simple for the user put the update in an EXE or Zip file.
Let the user download it in a reasonable time.
Disconnect from Garmin Express and install the update.
For what reason does Garmin need to be connect the whole time????
That is the way most companies do update installs.
Not stay connected to Garmin the whole time.