I got super excited about the USB drive support and started telling everyone who would listen about how it would solve all our work-related problems with transferring gigabytes of documents onto iPads securely. Then I tried using it with about 10 different USB devices, and was unable to use any of them to successfully copy a 10 GB folder with thousands of files in it into 'On My iPad.' Working with one file at a time was OK, but I managed to get Files into an unresponsive state that could only be cured with a reboot more than once by accessing and copying large folders. I’m convinced nobody at Apple actually tried to use iOS's USB support for “Pro” tasks – it doesn't work.