I know a lot of people won't have the patience to do the slow method, but there's a lot of small nuances involved doing Siu Nim Tao correctly from a NeiGung perspective, which is missing from the basic teachings from the Yipman lineage. The slow method was the true secret in the Wing Chun method. Done correctly over time, it will increase power and speed. If you dona search on Chu Shong Tin on Nim Lik or Nim Tao, he explains it well from experience and also demonstrates the power from doing it correctly over time.