viacad is hands down one of cleanest and most powerful 3d cad programs out there. a few bugs if you depend on part tree after a few to many saves, but note many. I used to use acad and inventor at work; now, only to open huge dwg files to purge, then to viacad pro. Bossmen even got solid works, almost comparable for drawing on...almost. The g3 commands make seamless blending on par with rhino, only maintain nurbs which are just better. The spline to arc is a wonder command for 2d gcode for laser and plasma. no little facets on parts from polylines.