Seconded, it is really massive and definitely on a scale with jira. As a downside you have to spend serious time to implement your workflow, but that would be the same with jira.
> As a downside you have to spend serious time to implement your workflow
That's actually the benefit of Jira.
It lets you define your own fields and workflows.
Most other apps force a specific workflow which may not work for your specific business reqs.