hi Asmo,
a lot of Hung Kyun players do it like wooden dummy, just moving the hands; on the other hand, exeggerated movements are imho not correct either.
we play the first 2 sections of fhsyk with body movements (rise, sink, swallow, spit), however, the movements are very subtle. there is always a body, waist and the stance behind the movement, even though it might not be obviously seen.
good inspiration is the way how some mainland WCH players do their siu lim tau (compared to Hong Kong WCH); check this (Wong Nimyi sifu; sifu of my friend - i have just visited him in Canton 2 weeks ago):
[youtube]http://www.youtube.com/watch?v=prTFbXgIM4Q&feature=related[/youtube]