We are currently planning to upgrade our three Jira environments to version 7.4.4. from 7.2.9.
Or rather, two of the environments will be replaced with new servers, one will be upgraded.
My colleagues believe it is an advantage to install our current version (7.2.9) on the new servers, and upgrade it to 7.4.4 alongside the third server. The argument for this is to ensure the environments are 100% identical.
I prefer to do a clean install myself, to avoid any issues which might be inherited from older versions, and to save time.