I must rate these shoes as high as possible. I don't know about the return energy spring but the shock absorption is wonderful. I work on a solid cement floor, walking fast most of the day. They have really helped with my heal pain. Feet are still tired at the end of a 10 hour shift but not painful or aching anymore. Now I still wear my arch inserts, these helped my arch Plantar fasciitis but not the heal. These shoes have really helped.
I tried to run one night in these and for whatever reason; it was really hard to get in my 2 miles. I think because they are heavy it wore me out. But for work they are great. Gives good stability and comfort all day long. I will most likely purchase a second pair.
Be sure to order the next size up from what you normally wear. It was recommended to do so and I did. These 11.5 are exactly what I needed. Normally wear a 10.5 or 11. If you have a narrow foot these may not be for you as they are wide. I wear a wide shoe so it was great for me.