martin heierling told me once: if he levels out the foot for those custom milled footbeds for alpine racers, 1/10 of a mm on one side more or less can change the angle for 1°.
well, i`ve got some doubts about this...but if it`s true you may get a better feeling for those numbers. they`re small but they have an impact. and i really can feel it.
as i said, i truly believe that the position of the feet is as unique as every human being. so i really don`t think that duck is the stance to go for everyone. it can be, in some cases for some people!
you`re right, cyclists do repetitive movements that can`t be compared with skiing. but what i`m looking for here is following: i`m looking for evidence which could "proof" that duckstance can be a natural position for your feet. and even if they do repetitive movements...it shows that this could be the position they got the most power with. so why not apply this to skiing?
i mean in the end every stance is just the result of taking averages. as you said, the terrain changes every second, and so does the distribution of your weight, pressure etc. you mount the binding in a position to handle the average skiing situation in the best possible way.
yeh the placebo effect

as i said, on my retest i didn`t have perfect conditions. but i felt like the straight mounted skis did perform a little better than i had in mind. so there is a placebo effect for sure, that made me remember straight skis worse than they actually are.
but the change from "straight legged" on duckstance to "knock kneed" on straight stance isn`t placebo for sure!
blind test would be a good idea. but i really doubt the accuracy of the results from such a test, because first of all you had to find 30 people with 100% healthy legs - which could be difficult as maybe 80% of our society have dislocated feet. so i suppose the result you`d get would be: some people like duckstance, some don`t like it and some feel no difference at all. the only useful conclusion of such an experiment would be what i already said: the position of the feet (and connected with this fact the preference for the stance) varies for everyone.