No relation to previous Endorphin models I have bought. The cushioning is too soft for my 82 kg, so it gets tiring as this "springiness" consumes more energy. The sole is something like styrofoam and the protective plastics that prevent wear (underneath) are very thin and with little use have started to come off... I don't believe they will last long. I give 3 stars and not less because the shoe is beautiful, comfortable on the foot (good fit), and when walking it's like wearing cotton on your foot. I won't choose the same again and I will try to see the shoe up close in a physical store before buying. I got tricked because I am a fan of Endorphin and I expected it to have the same quality as the previous ones.

Great shoe has improved a lot compared to the speed 3 I had is much more stable has a much better fit ties better to the foot you feel it like a sock as we say (lifts and half a size down if you want it to have a tight fit since it is longer than the speed 3 and leaves a little more space for the toes in front) the foam has tightened a bit which makes it ideal because the previous one was soft and sank a lot. An additional plus is the outer sole which is more slip-resistant due to its larger surface. Overall, the upgrade is worth it if you have the speed 3 I consider it the best of the whole series this particular model speed 4. I also tried the pro 4 which I liked more as a foam but I didn't like its stability it didn't hold you enough from wrong stepping so I went to the speed 4 which is much better in this aspect.