OK, we are firmware developers who use JIRA in a very advanced way with our clients, and we gave it a go and I just came back here to give the team some feedback because no doubt they are watching this very closely.<p>The killer missing feature for us is that we can't define different issue types. For example, we would typically have issue types like "Requirement", "Bug", "Signal", etc. with different icons and use child/parent hierarchies to sort these in a tree with this hierarchy: L1 high-level business requirement, L2 technical breakdown stories, L3 very specific requirement/bug/signal.<p>In line with this, there's no way to show the issue layout as an expandable tree-view (called "List" view in JIRA), and so our requirements tree would get all mashed up and flattened.<p>For each technical story/signal we would have a custom field where we set the source file where we are implementing it. This would help us hammer out the architecture of projects very quickly and have them line-up with technical requirements. Doesn't seem to be a way to add custom fields to different issue types. Later we would export this all out of JIRA to help write our documentation.<p>Lastly, a JIRA replacement without a corresponding Confluence replacement could be a bit of a point of friction. I hope that somewhere on your roadmap you plan to develop a basic solution to cater for the Confluence need.<p>Otherwise ... it looks nice. Have you thought about offering a self-hosted version, since JIRA no longer offers this?