I love Trello. I just started using it for work and school. My one and only concern is data loss. With previous apps I could ease this anxiety by simply backing up my data. I have never had to rely on any of those backups but if I needed it I could simply import and all would be back to normal. With Trello I have found this is not possible. Yes, I can download a JSON file of my data, but this certainly isn't the same. In the end, I would need to reenter all of the data manually anyway, so that feature seems pointless. Probably useful for coders and developers.
Anyway, is data loss something I should even concern myself with? Maybe not. Perhaps I should just relax and rest assured that my data is being professionally managed by the folks at Trello?