Once off the plane it usually doesn't take me more than 10 minutes to get to and clear the transit security station, but I really move it so that I can get ahead of "the pack" and be one of the first at security. My flight from the US tends to have quite a few passengers who are connecting to other international flights so if I dawdle a minute or two I'm looking at a much longer wait. It helps that there seem to be no passengers from other arriving flights at that particular time (about 4:30pm Seoul time).