So, I've seen the many tutorials on how to extract the 'ESD' .dmg install DVD image from the App Store Lion installer, and burn to DVD or a USB stick etc, e.g.
..and I've even tested my DVD out by booting from it, but I've not gone ahead with installing quite yet.
Just wondering, does anyone know if you can do an upgrade install from this DVD, or does that only become an option if you've followed the 'prescribed' method of running the App Store-sourced installer app directly? If you can upgrade from the DVD, what's the process? I'm finding:
a) it's not obvious from the initial menu when the install DVD boots how you'd select to upgrade, and b) all tutorials for installing using the burnt DVD only seem to mention doing an [erase, clean-install, restore from Time Machine or cloned backup] procedure.