I think autox has helped me some at track days. I tend to brake later than some of my track day friends. I kill them in the slower sections of the track, but I am not as fast on the big highspeed sweepers. The earlier posters are correct(at least in my case) that turning in at 100+mph scares the carp outta me. I can really push the STi in an autox without much fear of wading up the car. On track, I slow down a few extra mph in the highspeed sections, just to be safe. Cone marks are easier to buff out than wall marks.