How difficult is it to upgrade between different editions?
Upgrading JIRA: The JIRA upgrade process is very simple, and all data is seamlessly transferred between different JIRA editions. More details about the JIRA upgrade process can be found here. Upgrading other Atlassian installed products: Upgrading between different editions is even easier! All you have to do is to copy the new license key into the ‘License Details’ page in the product’s administration console.