I noticed this was an old thread and I thought I would check in and see if anything has changed. I too am using ArcGIS for AutoCAD to connect to a feature service running on ArcGIS Server. The feature service is actually a feature class in an enterprise geodatabase. It would be nice to edit the attributes for the feature service from Map 3d (2012, 2014) and still have access to the geodatabase domains. Is this possible with some customization on the AutoCAD side?