I went with the MyBook but got it from Best Buy and bonus was it was only $119.
You just plug it into the Cloud and use the safepoint tab of the dashboard. Select USB drive as the backup destination and you should be OK.
It takes a looong time to backup. I only have 800GB and it took about 20hrs. Subsequent backups only make changes.
The nice part is the backup files are exact copies not one compressed mess. This means you can take your backup and restore your files manually without a new MyCloud or WD software if you need to. They’re just buried a few folders deep but you’ll find them no problem.