With reaction time virtually nonexistent, the internal martial artist is able to change fighting techniques faster than an opponent can, and is able also to combine the normally separated areas of the body into one integrated, unified and powerful whole.
(Bruce Frantzis)

Not all tai chi is equal. Just as there are different models of cars, makes of computers and universities of varying calibres, so too are there different kinds of tai chi.

(Bruce Frantzis)

Sustained power

In the internal arts, first and foremost, you never have a second where you don't have power. Regardless of whether you are yielding or attacking, there is no time when you lack power in your arms or anywhere else in your body. That's how the internal arts are done, and it has many practical benefits. For one, it prevents exhaustion.

 This issue of unbroken power is a pretty basic difference between internal and external martial arts.

 (Bruce Frantzis)