Take the project below for example, there are over 500 Structural framing members in this building, with a large number of Mechanical and Plumbing fixtures.
The use of Revit's built in interference check saved valuable time when coordinating the Structural design with our Building Services team, and the models were soon talking perfectly with each other.
The clash detection will save you those embarrassing RFI's from site, and help keep the Services guys happy.
Make sure this is a tool you use, and not one of the things that is left in the background while you concentrate on producing those 2D documents to meet your managers deadline!
We are using a BIM program remember, not AutoCAD.....
Sorry guys, the image above is a high resolution image.... but for some reason will not let you click and enlarge it.