I find that when I'm writing to task, you know, seriously, deliberately, putting in daily hours and all that, I average about 400 good, fairly polished words an hour.

When I'm not intentionally writing, but I get bored and "accidentally" slip into writing, 400 words might take 10-15 minutes.  You can see how that might add up if I somehow don't come up for air for an hour or two.  I've written in excess 0f 5000 words dozens of time and breached 6000 at least two times I can recall.

When that happens though, I find the typeo to correct word ratio to have risen from 1:100 to more like 1:10 (multiplied by how many more words there are, you can see how this might get out of hand).

I also find that somewhere between 1750 and 2500 words, I'll have probably exhausted whatever was in my brain at the moment, and at the breakneck pace I'm drafting, the next words out of my fingers will venture out into something completely unplanned and even unconsidered, usually something just sprouting organically and spontaneously from conversation between characters.  This is often very interesting territory, at least from the POV of me discovering information about my story that I may not have put much thought into yet, but very rarely do these words inform actual scenes that will be present in the finished work.  Even more rarely do these forays into volume result in words that will see the light of day without being altered beyond recognition.

At least its not as bad as participating in the NaNoWriMo where I find I average about 2000 a day, but I basically work all day, hardly able to eek anything out during my normally allowable writing hours, then writing at the dining table all evening then staying up till midnight hacking away in the basement (where I generally get a third or fourth wind right about 11:54 and feel like I should stay up even longer to take advantage of it).

I much prefer working at my usual pace with my deliberate methods with usual limits on my writing times and days.  I haven't done the math, but I'll bet I get more readable novels per year out of one-fourth to one-half of the daily word count as compared to the other methods of work I'm prone to.  I do know that I feel much more sane that way, too.