As you know, AutoCAD and verticals can only xref 2d dwf/dwfx files, while design review can open 2d/3d dwf/dwfx files. I think if AutoCAD MEP can xref 3d-dwf files, we will can easily interoperate between revit products and AutoCAD vertical products.
Revit architecture is easy to create complicated shape for buildings, while AutoCAD architecture and MEP can provide detail design.
Now Revit can export 3d-dwf file as well, so if both revit and AutoCAD could xref 3d-dwf will be perfect.
