I am an academic and I have loads of reports, research, and other literature to write, process et al. I am also dyslexic and have M.E. Both of these combine in my need to find useful short cuts to completing everything I need to do, without expelling too much energy. One of these short cuts is to use computer dictation software. I have knowledge of PC and Mac software. On the PC I have tried Dragon http://shop.nuance.co.uk/DRHM/servlet/ControllerServlet?Action=DisplayProductDetailsPage&SiteID=nuanceeu&Locale=en_GB&productID=109252300&Currency=GBP
and IBM's http://www.nuance.com/viavoice/simplydictation/
software - Dragon is much better than IBM - but both are far behind MacSpeech Dictate http://www.macspeech.co.uk/
I know that access centres - the government approved places who assess the needs of students and employed people, in need of help technologically wise, to complete their studies / do their job (these technologies are provided by the government under the Disabled Students Allowance and Access To Work scheme) - will only suggest Dragon and MacSpeech.
I do not hide the fact I use apple computers. All other OS arguments aside, I would be completely lost without MacSpeech (I'm not using it now - so there maybe mistakes in this reply). Both MacSpeech and, I understand, the new Dragon (the version I have used an old one and did not do this) will allow you to sit with a microphone on and speak commands that will control your computer i.e. tell it to open the web browser, and navigate to a certain web site. This is really useful once you are use to the more traditional uses. When I used Dragon it took an age to train - I had to sit and read a book out loud until it ... eventually... understood my voice (with all these software's you talk slightly differently to how we speak to each other). Even once it claimed to have got it, there were many many mistakes. MacSpeech on the other hand took 20 mins and then I was able to start using it. If it makes a mistake, it always suggests around 10 alternatives it thinks you may have said - if it has got it wrong, all you do is to look at the alternative list and say "Use 3" and it will substitute its mistake for the 3rd suggestion. By doing this it is further learning your voice. I do not know about Dragon, but MacSpeech allows up to 4 users - so my wife can use it, alongside - when he is old enough - my son. The user experience of MacSpeech is fantastic, very easy to pick up, clutter free and works in all of my software - be that Microsoft Office, Apple iWork, all web browsers etc... I am not sure how friendly Dragon is in this respect. You can also get MacSpeech to read back what you have written if you want - not sure about Dragon.
With MacSpeech you get a decent mic & headset - the software is designed to work properly with the mic's they choose to supply - this is not the case with Dragon (it certainly was not when I had it - things may have changed), as such I feel it is more accurate and responsive. It also learns words - I use a lot of foreign names and legal terms. It learns these fairly quickly. I also know that the licence for MacSpeech allows you to put it on both a desktop and laptop - so its on both of my macs. My advice would be look at both of these routes. For my money I would pay the extra and get a mac and MacSpeech. In this type of software you really do get what you pay for.