I've been using omniplan but have found the limitations for scrum/agile development quite stifling. To the point that I no longer use omniplan except at the beginning of a project but it is only a bit better than omnioutliner in this regard...as we do not revisit the project items. We're back to using a whiteboard -- great, but not quite as "open" as the html export I've used as a much appreciated project update snapshot.