Yes, I tried both. Trying the -unlocked package, I successfully downloaded and installed it, but the configuration script failed. If I got correctly what happened (I may be wrong) the package downloaded two .deb files (one for rx34 and one for rx44) in /usr/share/osso-software-version/ and then the configuration script tried to install the .deb corresponding to my device (rx44). This attempt failed due to the lack of a set of packages: initfs-flasher kernel-diablo-flasher flash-and-reboot . I did the first time the update from the app manager, and once I saw it had not worked I used apt-get, seeing the error messages. The app manager did not reboot my N810 at the end of the upgrade, nor showed me any error message that could allow me to see that something was wrong.

So all the problem (in my case) was due to the accidental removal of a set of packages that should never be removed from your N810. I have been able to reproduce the conditions that led to the removal: a simple
from a newly flashed device removes those packages.