I'm self taught. Rode for about a decade and then took the basic course with my wife (gf at the time) because she didn't want to take it alone. It was a cake walk--the instructors had me wear a tiny cone on top of my helmet to make it a little more challenging. I could benefit from some racetrack-grade instruction--mostly on braking--but even at track days, I was one of the fastest few in Intermediate. (NESBA intermediate, where you have to be promoted by an instructor, not other track day clubs where you can pick your class.) I honestly don't think there's anything I could learn from an advanced class that was street oriented.
Don't get me wrong, the advanced rider course would probably be entertaining but my free time is so limited that if I had a weekend to go riding, I'd rather spend it railing the back roads.
'99 VFR800, '08 1125R, '06 1050, '03 Vmax, '03 DRZ400