After reading the threads about USB devices not working well on the MyCloud 3 and 4 Tb devices, I wanted to test something. I connected a USB 2.0 powered hub to the MyCloud and attached 3 USB drives, 2 of them were Toshiba USB 2.0 500Gb portables and 1 was an WD 1Tb USB 3.0 portable. All three drives and all their folders were immediately visible to my Win 7 laptop via the MyCloud.
This is just an FYI, something to satisfy my curiosity more than anything else.