The product struct is changed from 5.0 to 6.2. There is no other quick way to make an updgrade of Alfresco: take all customizations and create a project with the appropiate SDK. First with 5.0.0.c., then you need to check the path to upgrade according to it.
I know this action will take time (and money) but I think is the only way to ensure you won't lose anything.
My Ansible approach will work for any version of Alfresco, pre- and post-6.x.
However, the Ansible approach really just automates a manual install. It is still up to you to figure out the difference between configurations across releases.
For example, in their current state, the Ansible scripts install 6.2 community with Search 1.4. If you want to use them to install a newer verison of either ACS or Search, you can, but it is up to you to figure out that the config files are different in the newer releases.
This highlights the main difference between my Ansible scripts and what Alfresco will hopefully release later this spring. In my case, upgrades require some homework. In their case, hopefully their scripts will support many versions and will be able to deal with config changes across releases.