The refined Altra Paradigm 4.5 shoes perfectly fit your foot. It encapsulates without binding the foot. The cushion allows you to feel the ground in detail while providing traction when thrusting your stride and preventing any jarring or shaking upon contact with the ground. The padding construction and layers provide a cushioned feel that expands in compression during your upward movement cycle. Perhaps best described as the Oubleck stride, you never lose control, balance, or strength throughout the stride, but your joints never feel any jerk or pressure. I'm looking for a backup pair if my current pair breaks down. Given my experience with Altra, I'm sure the new 5.0 paradigms are awesome. I'm just not ready to give up such comfortable shoes.