What about installed packages? Is there a way to backup a list of installed packages and reinstall them after the "upgrade"?
That's what I do. I have a master list of apps that I use/need that are not installed by default. On the new installations I go into synaptic and build the apps from there. This way, you're getting the current stable release version that the repositories are supporting.
This means you have to install the operating system, and then you have to go back and install each app required.
Download BOOSTER from https://apps.ubuntu.com/cat/applications/booster/
deb or http://irajacic.com/downloads/
for tar.tg file ( you dont need to install this program as it is "portable"
You need to fill the application list with the required programs. To do so, click the Get Latest From The Internet button; this will fill in the left pane with all of the applications from which you can select. Next, search through the list of applications and add the ones you want to the Chosen applications pane by following these steps:
Locate the app either by searching the list
or by typing the name search box in the left pane and press the search buton.
Click the right-pointing arrow to add the app.
Continue with that process until all of the applications are added (Figure D).
Click the Generate And Export Script button. You will be asked to name your script — give that script a name like booster_install and locate it in your home directory. (Booster will append the .sh extension at the end of the file name.)
Once you've installed your new system run the booster.sh file answer the questions and it'll install all your progs in one go.
So basicaly make a list of you progs such as -
then use that list with booster.