We recently renewed our passports on line. They took 4 working days. We did pay extra to have then couriered back and sent the old ones by next day delivery.
We did have a long time left on the old ones, but with two holidays coming up we didn’t want to risk any delays, as returning from one country requires 10 months left on the passports. I’m so glad we did it.
However, I do feel very sorry for people who might lose their holidays because of the delays. Apparently under normal conditions they deal with 250,000 applications a week!