First of all, Rhino is the best in cost-effectiveness. Rhino was practically the only "USEFUL CAD TOOL" in this price range. (Ver.1.0 in those days) Second, we can handle Rhino comfortable, or Rhino requires less power of the machine. This is very important for designers how fast we can reach to the design surface we want in a short time. Finally, Rhino has the similar operation with AutoCAD. So I could transfer from 2D CAD system quickly.