Recently I decided to buy and use a pair of sneakers designed for skating instead of general purpose sports shoes I've been using. However, instead of reducing the pain and discomfort in my feet, new shoes significantly increased it. In order to ease the pain when wearing new shoes I had to change the angle of my pedals from 2.6 degrees to about 6 in order to feel more or less comfortable. The sole of my new shoes is completely flat, comparing to old ones that raise my heel bout 2 - 3 cm above my toes. It also depends on how much you bend your knees when riding. If you "squat" too much, then you should increase the angle to reduce strain on your feet muscles. The bottom line, try to experiment with your pedals angle and maybe your shoes as well, some people feel more comfortable with soft sole, others claim that hard one does the trick for them. I suppose its all personal, but can make a huge difference when your personal right combination is found.