So a client comes to you as a professional admin. Let's say they have
an aging Squeeze LTS based web server. They want to move to Jessie
which you may have heard is recently released. Would you re-install
their system to Jessie and ask them to reinstall their web site from
scratch? Or would you spend twenty minutes upgrading from Squeeze 6
to Wheezy 7 and then from Wheezy 7 to Jessie 8?