I have a 2014 Mac Mini with a 256 PCIe-based flash storage that loads up fast, but has no storage.
I added an external 1TB miniStack, but it was a pain to keep moving things around. So I picked up a WD Black 750GB 7200 RPM (WD7500BPKX) and the ifixit dual drive kit & TR6 torx security screwdriver (th . . .