dear mok,
thnx for the interesting topic. i 100% agree - most Hung Kyun schools have almost bad shotokan karate flavour, stiff, dead strength. in my opinon, Kung Kyun as so called "hard" system of gungfu is just one of the many bullshits out there.
one of my teachers said - Hung Kyun power is not like the one in taai gik kyun, nor like the one in karate. there always has to be softness in hardness, and hardness in softness. gong/yau, yeung/yam, fu/hok...
the correct power is very difficult to build up, most of the schools fall into 2 extrems - either no power at all, or stiff strentgh. ging is something else.
the power should be alive, flowing, not locked - ie. ging lik (coordinated, whole body integrated and focused power), not sei lik (dead strength - locked, isolated, muscular only). everybody knows that, but just few really can do it.
according to how we train, even the the tensed facial expression is not good - power should be somewhere else, and the spirit should be reflexed in the eyes, not in the face.
just couple of notes, hopefully others will also add their 2 cents. in my opinion, it is very important topic.