Dr. Jordan Yee demonstrated the end results of this training for me once. (We were in a restaurant, about to leave, and waiting while Mr. Hartman paid the check, I believe. If memory serves it was a Pizza Hut.) It was really something--I would just start to move and he'd be done hitting me. I was very impressed.

Is there a directory of Wing Chun schools/teachers? I found one:
http://www.wingchun.org/text/schools/kwoons.html