I started using at it a couple of months ago for a couple of small projects.
I think it has real potential as a tool for dealing with integration of old projects and new ones, and for charting out transitions in a production environment.
I have been looking at some 'technical debt' in the form of badly documented software written over several years (by several different employees) and it can be a nightmare.
YADA offers a simple, flexible way to organize these sorts of processes.