I love watching Tai Chi push hands work. I learn from what I like and from what I don't like. Push hands has some interesting advantages - and some fatal flaws built into it's methodology. This sounds like the topic I will be covering for the next few days.
Here is a video showing interesting technique from a master. I really enjoy this film. He really has some excellent soft touch manipulation of body mechanics.
The bad thing to watch out for is their ukemi, rolls and falls. It seems almost universal in the tai chi world (on you tube anyway) that once technique is executed the uke flies away out of control. In this film uke even crashes into the audience. In some other films by this group they are doing throws, with poor ukemi on concrete.
So like the Yin and Yang, I feel this offers a best and worst of push hands. Very nice application of technique and principles, and poor receiving of technique.