Yeah, I hear that. Our state course was a beast of a hilly course, where the first half mile was literally like a 15 degree hill slope... The best I ran there was 17:23, and the course record is like 15:23, but after that, only a handful of people have actually ever broken 16:00..
I wasn't fast, but I could maintain my speed. I'd be surprised if I broke 60 seconds in the 400 meter.