Yes, most people at OCS can do the run in 11:30 or better. In my class alone, there were 5 or 6 of us who could do it under 8:50, and one guy who did it under 8:00! You run quite a bit at OCS, but most of it is in formation at a very slow pace. It is running nonetheless and it is a huge part of PT, and from what I saw it is the one event that people improved the most on during their time there. Like I said, you do the PRT once or twice a week, and then once a week you do an individual 3 mile run as fast as you can usually on Saturday. As long as you go all out, all the time (that is, actually run hard and not slack off during the individual runs) you will get results.