I think the raw device default is that it does automatic updates, however as soon as it is configured via
www.obitalk.com the option is reset to not do the update automatically.
It's the difference between "Disabled" and "Periodically" in "Auto firmware update" (System Management/Auto Provisiong). While the interfaces suggests that "Disabled" is both the device and Obitalk default I noticed that it got set to "Periodically" after a hard reset (when Obitalk wasn't available.)
I don't know how the firmware updates are managed. Other companies newer devices are failsafe, because they install the firmware to a separate area then do a swap which only gets made permanent if the swap seems to succeed past a reboot. I don't know that the Obi does this, so it's safer to do updates as infrequently as possible; if the power goes out during an update there is a chance of having a non-functioning ("bricked") OBi. The only way to avoid this is to have the OBi on a UPS and do the update manually, the alternative strategy (which is not fail safe) is to simply do it as infrequently as possible.
John Bowler <jbowler@acm.org>