Excellent taxonomy. I think that many people who quote the various "10x" studies forget the fact that there is a certain percentage of developers who neversuccessfullycompletethetask. It's not just that some coders are faster (and more efficient) than others; a surprising number simply can't do the job.
I'd be interested to have the question answered, what is different for the hyper productive coders? Is it a certain approach or a way to think - maybe?
For example: if I have work to do that really interests me, I hack it down in no time. I can also speed my work up a lot, if I sit down in the morning and make a plan what I want to do and how I want to do it. The mental focus is completely different then: Its a competition with me, if I can stick to my plan and really get as far as I thought. Often it works fine.
On the other hand, if I have some really boring work to do, or I have to work with libraries which are full of errors and I spend my time debugging other peoples crappy code, it may take forever to get something done.
The problem is to work only on interesting things or to find something interesting everywhere. For example, if the coding is simple, I try to use a new and more efficient pattern to solve the problem. But it is not always possible to work like that.
I'm most interested in the last line of the quote at the top: "They found no relationship between a programmer’s amount of experience and code quality or productivity." Have other studies found this to be the case?
Anecdotally, I'd say there's a lot of truth to it. While nobody would dispute that a "visionary" or "trailblazer" with ten years of experience would be stronger than a visionary or trailblazer just out of college, I suspect the young visionary is a lot better than the experienced workhorse. Which is to say: experience matters, but not as much as which category you fall under.