What I came hear to say is a variation on this: ASK THE TESTERS! If your organization is large enough to have full-time system testers separate from the developers, they revel in finding obscure bugs and bringing them back to the dev team. They learn very quickly whose new code is bulletproof and whose is not. And they definitely know, once they've uncovered a bug, whose fixes stay fixed and whose just cause more bugs downstream. They don't a flying fig about lines of code, time spent on Slashdot, or anything else except 1) does the developer's code do what it's supposed to and 2) does the developer treat the testers with professional respect.