One draw back is that it's hard to beat the visibility and energy of Post-It cards on the wall in status swimlanes, but you also can't export the Post-Its into an Excel sheet to send to management for a quick status report.
Each project management tool I've tried has it's drawbacks.
- The Excel worksheet with stories, tasks and burndown was labor intensive to set-up or change very much, and often confused newcomers to the team.
- ScrumWorks is not intuitive, and couldn't show burndown on partially complete stories and tasks.
- The Post-Its can't be mass-updated, reported on, nor accessed remotely.
- Mingle doesn't have a burn-down (that I found, although rel 1.1 is said to have one), and performance is pretty bad.
Right now, the customer likes to see the project overview, and Mingle provides that at-a-glance better than the others, so I'll be sticking with Mingle for now.