I agree with a vast majority of this, except for the qualification of time.
There are many brands of mediocre programmer, some of which would claim a finished product well before the good programmer. But, the code will prove a nigh-unmaintainable disaster that will required all sorts of time later when a new feature is requested or bugs start creeping out.
There are times when a good programmer will take considerably longer than a bad programmer, and might spend time futzing around with different implementations, moving code around, creating various data structures, etc.
Depending on the task, I would argue that can be a good thing. The good programmer is attempting to understand and present a clear conceptual model of the problem and solution in his code; the mediocre programmer might just create a litany of special cases for the cases specified right now just so they can get that particular program behind them.
Although the mediocre programmer might produce code faster, I would argue the good programmer is still 10x more productive, because he has done that much more thinking than the mediocre programmer. Perhaps when you refer to futzing, you mean changing the code just for the sake of another commit to show management, where nothing is learned and nothing is improved.
Also, a good programmer might come back two months from now, with the knowledge he gained from some other project, and make a change to the program that tangibly improves it for the better. The mediocre programmer will have put all that behind them; it is not on their list of projects and requirements, therefore they won't bother, nor will they bother even mention it to anyone.
But, I suspect this sort of comparison of timespans varies with size, and with the difficulty of the problem space.
And yeah, N^2 different answers. :-)