Hi gmason, as some others have already replied, the main issue is not the size of the platform, but the stiffness of the sole and its ability to distribute the pedaling pressure over the sole not just for efficient transfer of power from the "engine" to your drivetrain, but to prevent the pressure from causing pain to your feet due to repeated stress to a localized area of your foot. As with any general statement, the devil is in the details - road shoes, in general, are designed to be stiff and inflexible for better power transfer. If the shoe is designed to be walked in, there is going to be some compromise in the design to make it more "walkable" (i.e., more flexible).