Speech to text, to me, is so attractive because it may help to usher in a whole new, even more powerful input paradigm than anything else in-use today. It's not about speed - it's about precision.
EDIT: A study demonstrating my point can be found here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3243272/
I have no idea how well current speech-to-text programs keep up with 150–200 wpm speech though.
(Short answer = that depends...and software like Dragon has many other advantages/drawbacks that factor in.)
"For myself, let’s compare typing vs dictating, given the above information and a 1,000 word email.
Straight typing: 90 wpm = 11.11 minutes, no proofreading allowance, correcting errors as typed.
Dictating with Dragon: 140 wpm dictating (7.14 minutes) + 300 wpm proofreading (3.33 minutes) + correcting 10 errors @ 10 seconds each (1.67 minutes) = 12.14 minutes.
For an average professional, typing speed is rated at 50 wpm. A 1,000 word email would take approximately 20 minutes to type.
For an average professional, their dictation with Dragon stats would approximate my own (12 minutes) — they are not unreasonable."
When dictating, you also hit the classical problem of your thoughts not forming fast enough to be able to formulate yourself in writing in real time, leading to a lot of breaks as you dictate. The guideline "think, then speak" of radio communication also holds for dictation, in my experience.
*more keystrokes but same time spoken, as the natural speech cadence is faster. Can't remember source right now.
source: grew up in the 90's in Silicon Valley
So either you speak really slowly or perhaps you should challenge the world record. I've been touch typing for more than 25 years (though not in Silicon Valley, so maybe I'm lacking some magical force as a result) and can comfortably sustain 60 wpm, bursting up to about 100 wpm. There's no way I can even come close to the rate at which I'm able to speak in a sustained manner.
[0] https://en.wikipedia.org/wiki/Words_per_minute#Alphanumeric_...
[1] https://en.wikipedia.org/wiki/Words_per_minute#Speech_and_li...
I did a stint at the Coroner' office as a intern. The doctor would at 2-3x speech into a tape recorder. I used to think he was trying to impress us by speaking so fast. "The patient had a descending artery over 50 percent occluded. The ears were symmetrical and no disginguising features. Pause Dotty--put a comma between symmetrical, and and)" Well I don't think he was showing off, just a fast thinker, and knew his job. Always wondered why he was concerned about a person's ears--maybe a pet project?
Anyways, Dotty would type those tapes, and hardly ever used the rewind button. To this day, I think about her typing skills. Nice person too.