I have been using this software for over 3 years now and have found it to be very easy to use and accurate. The cost of the software is also much less than its competitors. It has some unique features that its competitors don't have particularly its 3D polyline routines. The program allows you to cut cross sections without generating a tin or mesh (although it can generate these) to quickly get earthwork volumes. The routine uses the 3d elevation from your existing and proposed contour lines.