What’s the difference between Practical Method and other taijiquan or martial art?

Video in Chinese: http://v.youku.com/v_show/id_XNjkwODU2OTE2.html

Notes:

1. Master Chen when answering the question focused on Practical Method itself, and left it to the audience to do the comparison, as he couldn’t represent the other art.
2. Practical Method’s core is rotation. Spiral and silk reeling is rotation plus distance.
3. We can never do true rotation. It’s impossible for us to do 360 degree rotation. We can perform a lever action. A lever action is a part of a rotation.
4. Form training is to create levers in our bodies.
5. Grandmaster Hong Junsheng has the 10-word saying “Out with hand no elbow, in with elbow no hand”. Lin Ketong calls it 10-word mantra.
6. This mantra actually describes the lever action.