Perhaps the most significant addition was . Before 2006, if you needed a door of a different size, you had to create a separate block or manually scale/stretch it.
The 2006 release was defined by its focus on user efficiency and the reduction of "mouse travel." Its primary goal was to allow designers to keep their eyes on the drawing area rather than constantly looking down at the command line. autocad 2006
AutoCAD 2006 introduced "heads-up" design. Perhaps the most significant addition was