How long to write that short story?

In my post the other day about professional rates for short stories, I mentioned taking 20 hours to complete a 5,000 word short story. Now, by complete I meant the entire process--first draft, rewrites, editing, throwing the damn thing on the floor and screaming because I can't make the ending work. You know, the typical short story writing process.

I rarely write those 20 hours in order. Usually I take time off and work on other stories. My process is to write several short stories at the same time. When I tire of one story, or hit a roadblock, I put it aside and work on another.

But a few writers pointed out in the discussion thread that they consider 20 hours for a 5,000 word story to be paint drying, grass growing slow. Nick Mamatas laughed at my estimate, adding "Hey, I like my latte HOT, so step on it!" John Scalzi said that in "20 hours of butt in chair, I wrote and did the initial edit of 'The God Engines,' which is 30,000 words," and that he'd write a 5,000 word story in five hours. I've heard of other writers working like Scalzi, i.e., writing in a near complete final form. Isaac Asimov was famous for doing this. 

Of course, there were also writers much slower than that. Jeff VanderMeer asked, "Why the f*#& would anyone *want* to write a 5k story in five hours? Then you're just churning out product." Rachel Swirsky said, "I'm slower than slow. I'm glacial. The idea of writing a 5,000 word story in 5 hours is amazing to me; the idea of writing a 5,000 word story in 20 hours is sort of amazing to me."

So this set me to thinking: How long does it take most writers to complete a 5,000 word short story?

I kept track of my writing time this weekend, to make sure I wasn't wrong about my story completion rates. After waking up with a great idea for a short story, I wrote 5,500 words in 8 hours. However, this was only the first draft, which predictably had major deficiencies (namely, the language needed to be cleaned up, 2 of the 3 characters were one dimensional, and the ending didn't quite work). After throwing the copy on the ground and screaming, I rewrote the story the next day. Add another 4 hours. At this point, I'm letting the story ferment for a few weeks, but I imagine it will need another 6-8 hours of rewriting and editing before I send it out, so my 20 hour estimate is pretty reasonable for how fast I write. And I should add that several of my stories have taken much longer than that.

So people: How long does it take you to write a typical 5,000 word story?