I attempted to restore about 1TB of data (on macOS). Since I have 500mbit internet I assumed I'd be able to download it through the app, but that didn't prove easy. Even when split into smaller zip archives, the download would go terribly slow. Often, the archives would be corrupted and I'd have to re-download them.
In the end I had to order a drive to Europe (and pay the tariffs), which is a pain in the ass. (But they did return the deposit even though I missed the 30 day window.)
Edit:
Oh yea, and when you loose your data you have only 30 days to get it back before Backblaze deletes it as well! That's what happened to me right before a multi-week trip, so I was pretty unhappy that I wasn't able to download my backup in the 5-or-so days I had at my disposal, thus having to order the physical drive.