I had some success (five to ten years ago now) with having a Windows machine purely to run the dictation software, and using a remote access tool like x2x or synergy to pass the keystrokes through to a Linux box which ran my actual desktop. Obviously you lose some of the application-awareness but for people who need the voice recognition but find Windows drives them up the wall it's better than nothing, and it has the incidental advantage that the dictation software isn't competing with anything else for CPU and RAM.
