Here was my experience-

Sent my passport in for renewal non expedited service on January 25. Exactly 2 weeks later my passport still hadn't been found in the system. I called them to see if they had received my passport and also because I wanted to change to expedited service. I called and they couldn't find it, therefore couldn't do anything about changing it to expedited service. They said wait a few days and check back. 4 hours went by and I got the email that they had received my passport.

I called them back that same evening to change to expedited service plus expedited shipping. 2 days later and I just received the email my passport is being shipped.

The agent had asked what day I needed the passport by and I told her March 29. Had no idea the turnaround would be that fast.