So far my cleats have always been under the balls of my feet. The shoes and cleats I've been using allow for only one cleat position, as far as I can see. If I need to move the cleats, it might mean switching from my MTB shoes and Shimano SPDs to a road bike shoe/cleat/pedal system.
The idea of road bike shoes is scary. I'm thoroughly accustomed to walkable, recessed-cleat MTB shoes. I've tried on road bike shoes in the bike shop, and get the impression that I'd have to walk on my heels to keep from going sliding. Either that, or mess with cleat covers every time I get off the bike. What a bother!