Stock 10.1 2014 and USB HDD via OTG
FYI guys our stock Note 10.1 2014s have native support for USB HDDs via On the Go (OTG) cables. However, the drive cannot be NTFS: I tried a couple of different OTG cables, a powered USB hub for powering the HDD, etc, on my NTFS (a 2 TByte Passport) without luck.
I then quick-formatted the Passport to FAT and BAM everything worked perfectly: the USB device was recognized and the native "My Files" app auto-opened to display the contents of the HDD (i.e. an app like "Nexus Media Importer", which I used on my N10, is unnecessary)
Very impressive. I am diggin this tablet more and more...