I tried it years ago and it sucked. The learning curve was huge and it was pretty useless.
Now I even have it on my iPhone. It works great. There's even a Dragon Search that you can talk to to search the web. It works really good, too.
I think you'll like it, but you'll have to have patience with it and use it a lot for it to be a really useful tool. A really good headset is a good idea, too.
Make sure you let us know how it works out for you.