Usually 60 is run at the beginning of a showcase. Son had some of his best times running without a protective cup, ala Carl Crawford (remember this http://www.tampabay.com/sports...otective-cup/1110370) . Son would find some nondiscreet way to put it back in for skills set and remainder of showcase.
As others posted big factors as to time variances are surface, shoes, and whether you are running alone or with "competition." Like a good hitter who wants to hit the best pitcher's fastball, a good runner will want to run against (and beat) the perceived "best runner".