My first team lead was a 10x developer; I still remember searching for the j2ME code that would have taken us two weeks to complete that he wrote overnight -- I remember how dismayed I was to find it all directly in the keyboard event method instead of being spread over to various places it should have been.
So his initial code was a "10x" achievement, accomplished in literally 1/10 (or less) of the time it would have taken the team.
....but the legacy of his "10x achievement" was an increased maintenance burden. So the overall gain was less than 10x. Perhaps it wasn't even a net gain in the long run.
This is a good example of my main beef with the whole "10x" thing. So many superstar developers are lauded for banging things out quickly, while everybody else is stuck cleaning up 10x the mess.
I truly believe that there are 10x developers, but identifying them is nearly impossible unless the person doing the identification is (a) a pretty savvy developer themselves (b) is intimately familiar with the choices made by the "10x" dev and their long-term ramifications.
