Have a friend who has a mid-2014 MBPr. She wants to go to a larger drive, but standard offerings are only 1 TB (PCI2e/Flash). Other World Computing says they have tested the 2/4 TB drive from a MacPro, and it worked well, in fact actually faster (as a PCI4e). But, they don't "Offer" it, nor does Apple offer a larger drive. Is there a specific reason to not believe this user can go to a larger PCI/flash drive? Love to see her get the 4TB drive.