The home edition of Dragon will figure out you are in an EMR and will shut itself down so unless you copy a document from word or notepad then paste it into AC it is useless.
Here is my original thread on Windows Voice Recognition
http://amazingcharts.com/ub/ubbthreads.php/topics/29005/Voice_Recognition_in_Windows_7#Post29005

I still use WSR today with the added on vocabulary and as yet haven't taken advantage of all the utilities from the Windows Voice Recognition Toolkit.

That all said if Dragon Medical was 1/2 the price I would consider it.