The official help (Upgrade Zorin OS - Zorin Help) talks about saving all your data, then installing the new version over the old one, then reinstalling all your additional programs.
Is this because it's thought that typical users wouldn't be able to cope with doing it the 'apt-get update && apt-get upgrade && apt-get dist-upgrade' command line way, or has Zorin broken that? (I know that Linux Mint did do so for a significant period, which is why I stopped using it.)
Or is there, in fact, a GUI way to do in place upgrades between major versions?