The idea of the
sfos-upgrade is to get rid of the ‘tinkering’ -part of the command line upgrade into one or two commands with built in safety checks.
If it makes you feel any better, I did the upgrading through GUI with my Xperia 10 just before writing this and it was probably the fastest install of upgrade I have had with this phone so far. The GUI listed like 5 or 6
aliendalvik related packages “I should remove before the install”, but I ignored them because it was said to be okay in the “release notes” -post here at forums and I didn’t have any errors or problems during the install or after reboot.
During the installation there was flickering of the progress bar couple of times when the progress bar first appeared on the screen and couple more flickers when the installation ended just before automated reboot.
For extra safety, you can enable developer mode (write down the password) and enable remote access to the phone (from same settings page) and set USB mode to be always developer mode so in case the install goes fubar, you might be able to SSH into the phone over WLAN or USB-cable even if the display stays blank so could possibly save the need to go into recovery-mode. You can turn these settings back to your previous settings after succesful upgrade.