Re: Upgrading
Don't know if booting from an ISO will offer you to upgrade more or less automatically (if it doesn't, it should) - the command line stuff is not so difficult, mostly pointing at the new repository and then upgrading (but there may be other steps, depeding on your configuration and installed software).
Sometimes I do upgrade, sometimes I prefer a clean install and then move applications on the new ones.
Biting the hand that feeds IT
