Well, Dr Yang is NOT part of the yang family, even though he has the same last name. No relation at all.
He is a very acomplished martial arts master from taiwan nor residing in Boston MA.
He teaches Shaolin White Crane, Longfist and Yang Style Taijiquan. He is also an expert in chi na.
He has written over 59 books on chinese martial arts, and a lot of in depth books related to yang taijiquan.
His yang style comes from the lineage of Yang Ban Hou, chen fu's uncle. Its a little different from the one the yang jun teaches, although it has the same basics and content. The postures are a little different thats all, but they're really close.
I learned Yang Style from him, and I come to boston at least once a year to continue to study from him.
Some people speak highly of him, some dont. In that sense he is no different from any other martial arts teacher. This is something they all have to deal with. Everybody is entilted to an opinion, but those who have study his work have realized he is a great teacher with a lot of knowledge.
He is also firend with Master Yang zheng Duo and they have a really good relationship. Marter Yang Zheng Duo did some callygraphy for Dr. Yang's book on Yang Style.
Among his many publications are videos and books on taiji sword and broadsword, Thats why I named him in this thread.
I hope this helps!!!!