If the user's intention is to dictate some letters directly in MS Word or send email, then Preferred 7.0 is all that is needed. If you have a limited budget then Preferred 7.0 at $189 might be all you can afford. 

If the user needs to utilize custom macros then Professional 7.0 is needed. If you need extensive template capability, want to dictate directly into Lotus Notes or want to save the file so someone else is able to do the correcting then you must have Professional 7.  If you want the capability to navigate by voice in Excel, or other programs besides MS Word you must have Professional. 

If you are a doctor or medical professional you will likely need the Medical Suite 7.0. This provides a general medical vocabulary onto the Professional 7.0 version and works quite well for most specialties. If you are an attorney or legal professional you will likely need the Legal Suite 7.0. This provides an extensive legal vocabulary onto the Professional 7.0 version that includes court names, case histories, litigation abbreviations, subdivisions of legal documents, Latin and French legal phrases, hyphenates, state names, abbreviations, and postal codes.