Fresh Foam X 860 15

Expect comfort over pace. The top of the midsole is the softer, bouncier part and the base is firmer, so landings feel cushioned without going mushy. The forefoot doesn't bend; it rolls you through on its rocker, which is smooth at easy pace and slow to answer when you push. Heel strikers may find the first few runs clunky, and one reviewer said it smoothed out once they landed a little further forward. A couple of testers felt the weight as soon as they sped up. If you don't need the support, the neutral 880 v15 is a good deal lighter on our spec sheet.

Cushioning is the reason to buy this version. There's more foam under you than in the v14, and lab testing measured above-average shock absorption at both heel and forefoot, which fits with reviewers saying it takes the sting out of hard pavements. It's soft, but the firmer lower layer stops it bottoming out. One tester said their legs felt fresher late in long runs.

The support comes from the inner side of the midsole being firmer than the outer side along the full length, plus a raised inner sidewall, rather than a single post under the arch. Reviewers describe it as guiding the foot rather than correcting it, and lab testing found a wide, torsionally stiff base. That suits mild to moderate overpronators. It isn't a motion-control shoe, and it does nothing for runners who roll outwards. If you want firmer, more traditional support, the Adrenaline GTS 25 is one of the alternatives reviewers point to.