Vapo-Curious Friend: " I'm tempted by the Vaporflys but they're pretty expensive. I could wait until the marathon gets closer but then I won't have long to try them out before the marathon. And if I do try them - won't I wear them out? " Modern shoes don't need a lot of "breaking in". Don't believe the guy in the sports shop. If they are not comfortable on your feet when you leave the shop, they won't magically become so. They're not made of leather anymore which genuinely has a breaking in period. So that's my first point - try them on in a shop. Within 5 steps you will know whether they suit you. That said, the Vaporfly does have an impact on your running form more than most shoes as compared to a standard shoe they have quite an aggressive geometry in terms of stack height, an additional rebound due to the proprietary Zoom X Pebax foam and the addition of the carbon plate. They're also a big investment. Whilst it ...