Seems handy for the single application view. We use NavisWorks JetStream, it allows us to view several different applications simultaneously. We can merge DWG's with DGN's, DRI's, SKP's, or any of several dozen other formats into a single viewing session. That session can be saved as a Navis "Model" and the merged files act as "xrefs" would, every time you then open the Navis model the view is updated. We can also attach the supporting databases to this model and view the data that is associated with the models in the session. The model can be exported to a very compressed form that is viewable with a free (though very limited) viewer, that's how we share model reviews with our clients before they come in for the "real" review.
NW also has a suite of tools that include a clash detector that will capture, catalog and display interferences between 3D objects from the different application and an application that will tie everything back to your scheduling application.
