Thank you all for your time and commitment, i really appreciate it!!
Interesting, maybe we have a different culture regarding what is typically delivered. On most project i deliver 3D lines, layered and colored after content and/or date if you'd wish (DWG format). I can also deliver DTM's with or without contour lines, or just the contour-lines in a DWG (on proper heights). I use a Swedish software called Topocad. For land-surveyors its a real nice one-program solution since you can do advanced CAD:ing and handling with survey-data...
Drainage direction sounds interesting, is it possible to (relatively easy) convert 3D-lines (from DWG or similar) to more graphical 3D-lines? I'm thinking about the possibility to do a visual check for collision control? (Making sure the pipes are not drawn too close).
Is it possible to make cross sections between several DTM's?
My hopes are to keep my current software but upgrading my delivery by also giving something visually outstanding.