I have a set of the Shimano 600 version of these on my roadie. It is definitely both possible and practical to use them with regular street shoes, although it's not terribly comfortable. If you win them, just give them a try and see how you like them, and flip them if you don't like it. You might also be able to bolt in a small wooden block on the interior of the pedal where the cleat would go, to give your feet a more solid platform.