The H-Factor

Here at Hydratec we support users on all versions of AutoCAD, but primarily on AutoCAD 2007 or newer. When a user sends me a drawing I don't want to have to worry about whether I should open it in V50 or in V51 (both work the same for all usual support purposes). But, I don't want to send it back to them in a newer drawing format that they cannot read, either. So I have configured both 2010 and 2011 to automatically save all drawings in the 2007 format. You can do this in the AutoCAD OPTIONS dialog box:

Pick the Open and Save tab and set the Save As: to the AutoCAD 2007 format