Wideshut, I'd still avoid moving the old MBP HD into the 2012 13" MBP unless the old HD was very new and a higher spec than in the new product. Disks with spinning platters have reliability issues, the older they are the higher the chances of failure. Also any HD moved over would no be covered under Apple's hardware warranty. FYI, the PCIe flash storage SSD's are a long thin PCB, populated on both sides, interface on one end and held the the logic board by a single screw at the other. OWC sell (expensive, but cheaper than Apple's prices), but not for all Mac's. Not an issue with the MBP you are interested in.