To give Apple its due its refurbs are checked more than the new and I note suggestions they are all machines previously used is not correct. They sell inventory too, and on occasions even a boxed Apple where the box has been dented or holed they take the whole lot for rechecking and Quality Control ensures its received more attention than a new device and they stand by the warranty to prove it.
No doubt some may have been returned where its easier to swap out to keep customers happy, and then that machine too will undergo extensive checks.
No doubt some may have been returned where its easier to swap out to keep customers happy, and then that machine too will undergo extensive checks.