I started out on Preferred and I didn't feel the performance was there. I found a copy of Medical 8 on eBay, and then later upgraded to Medical 9. I felt that I experienced a major improvement in performance.
The major deficiencies with Preferred are the lack of medical vocabulary, and the inability to create macros.
This is why I was excited to see Tom's post on another forum, where he described adding KnowBrainer and KnowBrainer Medical Vocabulary to Preferred.
I saw this as a way to get AC users excellent voice recognition and command and control capabilities for $300-$400 less than buying the medical version.
