I don't experience any soreness. I've noticed that there is pressure. However, I find that as my body position adjust even slightly my body weight shifts back and forth across my foot. This releaves the pressure, or at least moves it.
I also do it barefoot on a padded carpet, so mine is not the worst case.
What I found the most awkward about the stance is having your feet parallel. You know removing that little bit of pidgeon toeing that most people do. When I shift my feet, that's when I feel the increase in pressure on the ball of my feet.
I think it's time for me to watch the video tape again.
You are perfection,
Iam2 
