The option that we have instituted is to backup the imported items folder to the cloud, using an encrypted service such as Carbonite (which monitors the imported items folder and backs up new items overnight)
Then we do AC backups nightly, without including imported items. And the AC backup folder is also monitored by our cloud backup service, and backed up nightly.
This saves us from repeatedly sending a 10GB file to the cloud.
Now if only AC would implement a full and incremental backup solution...
