I tried it two years ago and it did not work for me. In the end, there were more corrections I had to make than anything else. I only did one paragraph with that thing before I got tired of it and went right back to typing. It might be better now, though, but I am scared to try it again and then find out I wasted my money.
Yeah, training a voice-recognition (VR) program is a key element to its efficiency. I once input about half of a handwritten novel using a VR program. It gets better the more you use and train it, but it still makes mistakes. ('Training' means using the correction tool within the program, not just manually correcting the manuscript in the word processor.)
That's why VR isn't much help for people with severe dyslexia: they won't see the errors the VR program makes any better than they see the errors they type themselves.
In my experience, VR doesn't save time, due to the time spent training and correcting. It didn't take
more time over the course of that half-novel I did, but it didn't take
less, either.
IMO, what VR is good for is people who have issues with their hands, such as a repetitive-strain injury or arthritis. You definitely TYPE a lot less using VR.
But over the course of the work, it takes the same amount of time, it still makes a lot of errors that need to be spotted and corrected, and actual editing is nearly impossible. (By 'actual editing', I'm talking about things you do during rewrite such as deleting sentences or paragraphs, moving phrases around, inserting a word here, deleting a word there, changing a three-word phrase into a single word or a whole new paragraph, and so on.)
It also does nothing about punctuation and grammar errors. If you forget to speak the command for a period/full stop, it leaves it out AND doesn't capitalise the next word. If you speak a comma in a place that renders a comma splice, it inserts the comma right where you told it to. If you speak a plural verb for a singular subject, it types exactly what you said.
Finally, Philip Pullman tells a wonderful story about his wife reading his handwritten manuscript into the computer using VR. The mailman walked by, the dogs started to bark, and the program typed 'bark bark bark'. Seeing this, she started laughing, and it typed 'ha ha ha ha'. Right in the middle of his scene!
Anyone who thinks that all they have to do is speak into the microphone using VR and they're done has a big surprise in store.