In Tango, the initial weight has to be primarily on the ball of your feet. That is what helps you to pivot. As a result, my balls of my feet are as hard as my heels. But my heels are as soft as my cheeks. Because they barely bear any weight. This is what my feet looked like during the festival, after extensive advanced workshops and all night milongas.
These shoes went with me brand new, with the tags. And they were used only for the workshops, not even milongas. They never came back with me. Because this is how they looked like after the extensive workshops. In fact, they lasted for only first few workshops. The heels were intact. But the forefoot (specially the ball of the feet), were finished.