Based on the progress bar, it completed about 2% of the backup in the first hour, but then I noticed it moved to about 5% after another 30 minutes, so I left it alone. After the first two hours, it had made it to about 15%. That's where it was when I went to sleep. When I woke up, the backup and sync was complete. So, I have no clue how long it took, but it was only at 15% after 2 hours. Unbelievable!
Anyway, thanks for the response. I'm somewhat of a relief to know that this was a somewhat typical issue.