No external thank you. I'm not buying an all in one octopus. Apple can go [whatever] themselves.
For my particulars, I need about a gazillion VMs on local storage. They're not accessed often enough to pay thousands for enough SSD, and the iMac(Pro) only has space for one anyway (4 Tb won't cut it). So I need at least one spinny disk in addition to the system SSD. I am not willing to put said disks on thunderbolt, usb 3.14159 or whatever, I want them inside the case.
