Will update this as it continues, but hopefully seems like things are moving quickly!

Summary: regular / routine service passport renewal application, 3 weeks from mailing in to receiving new passport back --

• Fri Dec 29 application sent by priority mail envelope from CA to Irving TX
• Tue Jan 2 USPS reports mail delivered (note holiday weekend)
• Wed Jan 3 received in status system with email notification
• Thu Jan 4 check is deposited/posted according to bank account
• Thu Jan 18 application approved (email 10pm), and 2 hours later, email: shipped (shows Tucson as origin)
• Mon Jan 22 passport delivered by priority mail; received email notification that supporting documents mailed.
• Mon Jan 29 received old passport back

I tried to time my application for when I would not be traveling for at least 1-2 months, and when I thought would be a slow time for people applying for renewals given the holiday season, before people's travel plans and realization starts increasing in the new year.

Btw, not sure where people are finding the "location code" that tells them what office produced the passport? None of the communications to me contained such info.
Edit: application # / locator 45 -- this does not seem to correspond to any of the listed locations in the wiki. Returned passport came in envelope with return address Sterling, VA 20166-1108 but postmarked/meter from zip code 03801 (Portsmouth, NH?).