I need to switch frequently between Mechanical Desktop R6 (AutoCAD 2002 based) and another similarly capable CAD with good command compatibility. I'm currently using ProgeCad 2009 to tutor a friend with no previous CAD expertise and he is picking it up well and enjoying it. ProgeCAD gets a big thumbs up from both a long time AutoCAD user and the new recruit to mechanical CAD. It is truly capable enough for professional use, easy for Auto