There are issues with the survey database properly handling grid & ground coordinates when using a drawing on ground coordinates that has a user-defined transformation allowing you to maintain geo-reference. The survey database assumes coordinates are grid and scales them up again even if you are not working with grid coordinates.
This is a huge problem for my company and prohibits us from using the survey database at all. An extensive discussion on this issue can be found at the link below:
http://forums.autodesk.com/t5/AutoCAD-Civil-3D/Survey-points-with-ground-coordinates-are-scaled-inse...