How fast should we do our Form? How long should it take?
This can in part,depend on the style of Tai Chi and the length of the form. The short form and long form I learned from John Kells took me about 8 and 20 minutes respectively. John said our long form should be performed a bit slower, taking up to 30 minutes. My Sun style teacher, Dave Martin, told me that Sun Jian Yun said the Sun form should take about 8 minutes.
The danger is that we get hung up on how long it has taken us to do our form. Instead we should be focusing on the principles. Regardless of whether we are moving quickly or slowly. Each posture has a beginning and end which, without fudging,smoothly connect to the next posture. Are we relaxed and alert? Did the waist position the steps?
There is an internal flow, an aliveness to our form. It is possible to move too slowly and you end up practising being dull. Equally it can all go out the window in trying to move too fast.
We need to explore how slow/fast we can move and still remain in accordance with principles. Only then will it be correct.