Timescales for my application have been as follows:
7 days for documents to be marked as received from the date of delivery to Passport Office
22 days for documents to be marked as processing
15 days and counting in processing.
I submitted my application on 3rd February when the average wait time was three weeks. Wish the website was more transparent as if I’d known it was likely to take this long I would have paid the extra for the fast track application.