About the pushing hands videoclips
Oh, I think I should make some comment.
First I didn’t present the links to those videoclips with aim to show how good tui shou practice should look. Not at all. I used them to make point that such demonstrations as on Cheuk Fungs videoclips are not anything mysterious and impossible. When there is big difference in skill, it’s nothing special. Because it obviously was ‘a demonstration’, so I offered those 3 videoclips, where it is not an arranged demonstration, but a sparring. And you could see what can happen when there is difference in skill level.
Of course on the clips only the assistant of master Yao has good skill, not his opponents, which are my students, but actually very beginners. They just started coming to me a few months earlier. And actually it’s very difficult to teach them because they tried to learn some taijiquan for many years before, but without guidance of a good teacher, and without knowing what it’s actually about. So now it’s difficult to correct them. As it is said “it’s easy to learn, but difficult to correct what was learned wrong” 
Now about the Yao’s assistant. It may look very strange to some of you taijiquan guys what he is doing, but he is good at yiquan. You should know that yiquan is not taijiquan. While there are some close points, the main principles are coming from somewhere else. Presently yiquan is still not much known. Quite often there are some taijiquan people who also learn some basic yiquan, and they sell their idea of yiquan. But it’s quite different. Have you noticed that from the early period of history of yiquan (1920s) there were young people coming to learn from Wang Xiangzhai and after two years or so, they participated in free fighting tournaments or tournaments of western boxing? You think that the training was all about the internal principles? If they did pushing hands the way as in taijiquan, after some years they could show those skills which are typical for what you do in taijiquan, but could they participate in boxing tournaments after just two years of learning? Would those of you who think have some achievement in taijiquan pushing hands skills come out and fight in boxing tournament? Well, what they did and what we are doing now in real yiquan, is getting fighting skills very fast, using methods sometimes close, and actually inspired by western boxing, and then gradually making the skills more subtle. Yes, Wang Xiangzhai defeated some european boxers, but at the same time he was picking up some training methods of the boxers. Then Yao Zongxun was very interested in boxing even before he started learning from Wang Xiangzhai. So when he started learning from Wang Xiangzhai, he incorporated boxing bags, more sparring in boxing gloves etc. Wang Xiangzhai approved those changes, making Yao Zongxun his assistant and letting him teach in his name, and presenting him a honorary name with a meaning of being his successor. I write this, because it’s real history of yiquan development and how yiquan looks like, and not what some people imagine, not knowing more of yiquan than some basic zhan zhuang. Well, as some people said, that it’s only Yao Zongxun’s changes to yiquan, and not what Wang Xiangzhai was teaching, I can say: do you know of Zhao Daoxin, who was one of the earliest Wang Xiangzhai’s students and winner of tournaments, and read his “Daoxin’s theory of martial art” (Daoxin quanlun). It would shock some people who have funny ideas about yiquan. Or Han Xingqiao, who started learning from Wang in Shanghai period (together with brother Han Xingyuan, but learned from Wang for much longer than brother), and how he used boxing-like training? Or Bu Enfu? And many, many more (at least those who really learned form Wang Xiangzhai, not only some zhan zhuang for health). You see, it comes from real fighting practice, and not just playing pushing hands. It’s to make you better understand, that yiquan pushing hands is not based on taijiquan principles, and it’s closely related to boxing-like sparring. You may play with the principles, and get subtle skills, but in yiquan it was about fighting, about boxing-like sparring, and making pushing hands part of this. This is why it is said that pushing hands is not for pushing hands, but it should serve free sparring. So we think about place of pushing hands in boxing-like (or more thai boxing -like,as there is usage of elbows and knees and other parts of body) combat. So our tui shou is actually a part of this kind of san shou. Tui shou and san shou supplement each other. We use tui shou in san shou, and in tui shou we practice as it was part of san shou. For example leaning - this is typical for yiquan mechanics of generating power, and it comes from boxing-like sparring practice. Because Wang Xiangzhai’s principle was: “It doesn’t matter if it’s internal or external”. As Yao Zongxun said: “Yiquan is neither internal nor external”. We don’t insist so much on ‘internal principles’, although you can find them in yiquan practice. But yiquan concentrates much more on combat practice, and the training methods are closely related to this practice, and we use what is useful from this point of view.
Just to let you know a bit about yiquan 
Andrzej Kalisz
yiquan@yiquan.com.pl
http://www.yiquan.com.pl