I have or have had Candy's Smartys, Mallets and Quattros and I wouldn't want to ride on the Eggbeaters mini platforms in regular shoes. The eggbeater springs extend above the platform. So really your only point on contact with the pedal is those two little wiry sections of the spring.

Two options to consider - If you are intent on the candy's locate something like the winwood decksters that snap into the springs and provide a platform for your use when you want regular shoes. You might even be able to score somethng at your LBS that they use for test rides. Second look at something like a Campus pedal that is spd on one side and platform on the other.

On the other hand, if you use a walkable mountain bike shoe without cleats, the spring will rest in the cut-out cleat area with the soles of the shoes resting on the platforms. But as the soles wear, you end up more and more on the springs so that could get expensive.