We've recently made the switch to Advanced Roadmaps. We were using custom issue types and custom link types to represent an issue hierarchy. We have switched to using the Parent Link custom field in Advanced Roadmaps.
I have found a number of non-obvious constraints which I'll publish as a discussion. Firstly, I want to raise awareness of these issues for people transitioning to AR so they can set their user's expectations and, second, I'd like to hear from the community and collect more that I haven't hit yet. I have linked to the Atlassian feature request/bug (where available) to track them.
Note: This is for Cloud version of Jira Premium.
As a side note, if anyone else is moving from custom link types for hierarchy to using Parent Link, I have written up a procedure to do this programmatically. Let me know if there is interest and I'll publish it.
Before I list the constraints I just wanted to say that I'm loving Advanced Roadmaps. It's a great tool. The constraints below are intended to increase awareness and assist the community, they aren't intended to be a critique of the tool.
Here are the constraints I've found so far:
I will try to keep this up to date with further issues I find and with feedback from the community.