Royal Mail have been pretty good for me, usually delivering 48 hour within 48 hours after first scan. Personally I think the reason we're seeing these messaged from AL is more likely because AL have purchased the labels and either; missed collection, not packed it yet or not enough room on the RM wagon to fit all the yorks. The amount of times in the past I've seen this from other companies as well, not just AL.
Best I've had a few times is its arrived next day
Worst I've had is it gets sent to the wrong delivery depot then redirected, usually taking a couple days extra. Or for my first Gundam Mad order managing to send it to the wrong delivery depot... Twice
Maybe worth splitting from
@FathersBane post onward to some sort of Postal Rant thread
@Rui ?