BACKUPS TO CLOUD SERVICES like Amazon Drive is not a simple task, particularly if you want to backup to a specific folder.
SYNCOVERY: Syncovery on Mac and PC can backup to Amazon Drive. But it has a painful and clunky user interface. And the backups are slow.
ChronoSync, my favorite Mac backup app, has still not linked up to Cloud Services after years of asking.
ARQ BACKUP: Currently, I use Arq to backup to Amazon Drive. It does a great and very efficient job. But it is for backing up whole drives, not to specific directories on Amazon Drive. I like it since it will encrypt the backup before sending it to Amazon. The primary problem is that restoring the files is a very slow process. This is why I also simultaneously backup using CRASHPLAN. If I need to retrieve a single file, CRASHPLAN allows one to do so quickly.
ODRIVE BACKUP: So I am willing to wait for oDrive's solution to backup. It will make it much more useful a service.
SYNC LIMITATION ON LARGE DISKS: One limitation of oDrive Sync I did not realize is that Synchronization of files is a huge task - particularly if you are synchronizing large drives. So thanks to Tony of the oDrive Team for pointing this out.
oDrive can saturate your CPU and Bandwidth if allowed to run freely on a large drive. So I have to compromise and reduce its CPU and Bandwidth use to keep it from taking over my computer. I have to turn off oDrive when using Video Conferencing apps like Skype for Business since oDrive will hog the CPU and Bandwidth and degrade the experience. Luckily, oDrive allows you to limit the amount of bandwidth and CPU use to allow you to use your computer.
DropBox does synchronization very efficiently - much more efficiently than oDrive. So I disengaged oDrive from DropBox to minimize CPU and Bandwidth use.
AMAZON DRIVE, GOOGLE DRIVE, MICROSOFT ONEDRIVE FOR BUSINESS: I use oDrive primarily for synchronization to Amazon Drive, Google Drive, and Microsoft OneDrive since their apps do not do synchronization very well at all. For this purpose, oDrive does spectacularly well.