Hi guys, Just finished upgrading the 1tb drives in both my new minis to 2tb. I used seagate backup plus slim external drives, which when opened (a little heat really helps to soften the tape) have seagate momentus ST2000LM003 2tb 9.5mm thick sata drives inside. Disassembly and assembly was straightforward, using the ifixit guide. I found a T8 fit better than the recommended T9 in the drive screws though, and I used 2mm hex keys in lieu of the logic board removal tool. The first one took about 40 minutes. The second one was about 15 minutes work. The Seagate drives are a perfect physical match for the hgst drives that come stock. On reassembly I used Internet restore to restore OS X, and brought my data back from a time machine backup on a usb drive, which worked perfectly. It even refusioned my fusion Mac. For extra credit, I bunged the 1tb drives that came out of my macs in the seagate enclosures, so now I have a pair of 1tb USB3 drives too. So now I can double my movie and tv collection.