I apologize if this was already posted but Master Sun moves extremely well for his age along with teaching some applications.
Demonstrating Ba Gua Zhang fighting techniques & applications featuring Grandmaster Sun Zhi Jun 孙志君, the 4th generation of Ba Gua Zhang, and his disciples Master Wilson Wu 伍世龍 and Master Bruce Lin.
http://tw.youtube.com/watch?v=rA_AuE5Z0ZA&NR=1