We often work directly with civil engineers who are stuck in Autodesks Civil3D world. I know that the suite of tools they use to model terrain, roads, and sites isn't too far off from Vectorworks site models and site modifiers.
Everytime we try to collaborate with Civil3D users, we have to dumb the data down to a base .dwg and in doing so we lose a lot of what Civil3D calls AeCc objects. These have a lot of information included that is useful, including the basic graphic attributes and operability.
It would be awesome if the import commands for .dwgs or whatever file type is best can better aide the interchange between the two programs! And for that matter, the interchange should work both ways. I should be able to send files with objects that a Civil3D user can easily use and manipulate!