I received my renewal in exactly 14 days after it was received in the processing center. I did a tracking when I mailed it. I was shocked. On the form DS82 you complete for renewal, is a section that tells you where to mail your paperwork. If you pick some other location on your own and mail it there, perhaps that may add to the length of the process. Can't be sure. Maybe I was just lucky. However, I would stick to the address on the DS82 form for Passport Renewal. This is what is currently on the form. Good luck.
FOR ROUTINE SERVICE (If you live
in CA, FL, IL, MN, NY, or TX):
National Passport Processing Center
PO Box 640155
Irving, TX 75064-0155
FOR ROUTINE SERVICE (If you live
in any other state or Canada):
National Passport Processing Center
PO Box 90155
Philadelphia, PA 19190-0155