I've had a few recent order with CRC that have definitely used the full "3 working days" - as in order Wednesday arrive Monday or order Tuesday arrive Friday. I guess it's only annoying as I've got used to them being quicker, so they've turned up later than I've expected. Although I guess as this thread is about picking your supplier according to how quick stuff arrives it matters and CRC seem to have slipped behind some of the competition a bit.
Also I did have one thing marked as dispatched, but it didn't appear on Parcelforce's tracking for over 24 hours - so it's clear that "dispatched" doesn't mean it's left the building.
I gave up paying for next day from Wiggle as it was always the day after next day, and the free postage stuff turned up quicker.
Tweeks were very quick when I used them recently - definitely proper next day.