Here at ValleyCrest Landscape Development in Orlando, we us about 6 digitizers in the estimating department. I currently have one connected to my computer also but do not use it with Autocad. If I have a .dwg I just measure my area on my screen in model space. Digitizer is useful with hard copies of drawings or plotted PDFs which is starting to be the norm. There are of course cheaper ways to measure areas than buy spending $2400.00 on the cheapest roll-up digitizing board. Now Adobe Acrobat measures area, Brava, and numerous others are out there. Some even color the areas and give you print outs in excel format. I would check the other options first before forking out the money for a board. You can get almost any drawing in PDF format now, just by contacting the owner, architect or engineer, and is emailable too.