I have not, but don't let anything stop you from practicing what you can. Many instructional videos are available, and luckily you've found this forum with many highly experienced practitioners. Soak in as much information as you can, then practice 24/7 - make it a lifestyle. You'll keep what you find works for you, and discard what doesn't, but never discount what is historically shown to be the best. Standing post, yang long form, 8 pieces brocade, pushing hands, applications drills and sparring, meditation focused on enhancing your energy/chi circulation. Stuff like that can really really benefit, and it often may not seem to be greatly useful until you've experienced the benefits from training it over several years. It's like becoming a doctor or master electrician... you don't get good at it for many years, and there are always new things to learn. I laugh when people who haven't trained talk about how they can go about fighting better than someone who's trained it long time... Even when speaking about karate. Only experience shows, mouths running don't. I'll be the first to admit many have much greater knowledge and abilities than me. If I'm lucky I'll have a chance to learn from them. Yang Jun direct descendant from legendary matters like Yang LuChan (the invincible), or Yang ChengFu who brought tai chi into the open and who's students where renowned for their skill... Who trained and taught alongside Sun LuTang - one of the highest level martial artists in history. I'm sure his grandfather Yang Zhenduo has shown his great knowledge and abilities countless times, and being the lineage holder of what I see as the greatest martial system and the best thing you can really do for your health (alongside qi gong practices)... I may not be lucky enough to train under Yang Jun, but some who are here have. Listen to them, luckily these people are usually quite kind and willing to help.