The ST-3 is a straightforward, no-frills, versatile shoe for the person who wants to own one athletic shoe to do a lot of things. It has a simple design and is feather light. This makes an excellent choice for a combo gym and light mileage running shoe. The 16 mm sole provides some cushion but allows for great responsiveness during workouts. The heel of the shoe can be collapsed which makes it a great option for a travel shoe or slipping on quickly.