Here is a great Video n optimizing it when you get your hub ....
Works well on the ts4k with a 32 gig usb 3 stick no decrease in performance. Increased live buffer to 5hrs watching from hdhr prime cc. I to am now waiting on a hub for the Google Chromecast. Wish I would have thought of this long ago it would have saved me from trying so many different devices looking for that balance between performance and storage. Thanks for pointing me in this direction.
After a brief review, I've found a USB3 flash drive works well for extra storage, even over USB2 buses. However, USB2 flash drives seem to cause issues on the same devices.
Of course, this was over a host interface rather than OTG, so I'm going to try that next to see if USB3 flash drives over USB2 OTG are sufficient for expanding the buffer. (Or, maybe the 5 cables I bought to do this over USB OTG were all in vain and can only be used for Flirc devices.)