As an instructor, of course I would say yes, it's way to easy to develop bad habits and never know it. As an instructor I take at least one class myself, as a student. This doesnt count all the skill development courses we do. A trained set of eyes wont hurt. For those interested in the Puget Sound area, check out
www.pugetsoundsafety.com , they offer a wide range of courses, from the Basic course, through advanced street skills. They also offer the Lee Parks Total Control clinic, and several levels of dirt courses, to include adventure camps.
So, yes, get some more, even Rossi has a few coaches, so if he needs them, I would say it's safe to say it wont hurt the average rider.
Chet