Currently the Civil 3D Connector (_ARCGISCONNECTOR) saves back all entities in a given feature regardless whether it changed or not. This effectively overwrites all the data in GIS with every save back. It would be far more useful if it only sync'd back new and edited objects. This would also allow multiple users to write to the same layer without overwriting each other.
ESRI's ArcGIS connector for AutoCAD syncs data back to GIS for only new/edited objects. The limitation with that connector is that it does not recognize civil 3D objects.
