Update.
I got in touch with a couple of people who collect from T5 several times a year and they both said no problem with the "quick pickup".
However, I decided to try the Short Stay car park pickup (Yes,I know - a little too cautious!). Anyway it worked well. My wife said she prefered it as it was more civilised for her to just go to the Short Stay car park level 2. When I arrived she was waiting there in the dry. The only slight inconvenience was while I loaded her suitcase she had to nip back to the machine to pay the charge (£4.20!)
Mike