Hi @Jorge RM
I understood that when there is a change in the status of an issue, then it will be assigned to a specific user, right?
You can do this with both, however using Adaptavist you will have to program, that is, write line of code.
Now, using Automation for Jira you will not need to write a line of code, as it has a friendly interface for you to write rules that Jira will obey.
I'm happy to be able to help. =)