[Milhouse]

If the latter, whats the best way to accomplish this without losing your settings & library?

So long as you have ssh or Samba enabled, and the device is booting, you can roll back to an earlier build by copying the older (working) tar file into "/storage/.update" (ssh) or the "Update" Samba folder, and rebooting. If the Kodi GUI is working you should also be able to roll back from within Kodi (see note #7 in the first post).

In general, rolling back should not lose your settings and library although it is possible that you may roll back to an older database version in which case you will be missing recent library additions. In addition, there has been a lot of change to the Settings system in the last couple of months and if you roll back far enough you will lose settings as the guisettings.xml in current builds is not compatible with builds older than early July, in which case your settings will revert to default (old settings will be upgraded to the new settings format, but settings in the new format will not be downgraded to the old format).

If the device no longer boots then you can recover it by mounting the SD card in a PC and extracting the last working firmware, KERNEL and SYSTEM from the tar file. This is pretty rare though, as all builds are at least boot tested before publication - no boot, no publish.