I'm a one-man show at the moment working on 3+ repositories on Bitbucket. I tried using JIRA for a few months late last year, and it wasn't a great experience or me, so I ended reverting back to using the Bitbucket issue tracker. If I get the time to write an issue exporter (or find one that works), I'll be migrating to Github or something with an issue tracker that gets attention.

The problem with the issue tracker on Bitbucket is that it's not getting better because it would 'cannibalise JIRA' sales, but it's ridiculous that in 2015 I still can't create links between issues, or create subtasks. If I had to pay for a better issue tracker that's built-in to Bitbucket (no JIRA), I'd pay it.