Adizero Prime X 2 vs Rocket X 3

With 50mm under the heel, the Adizero Prime X 2 sits a full 10mm over the World Athletics limit for road racing, so no record or championship result run in it will stand. adidas built it that way on purpose, as a carbon-plated experiment in how far stack can go, and most reviewers ended up treating it as a very expensive super trainer rather than a racer. The softness won nearly all of them over. The weight was a different story: it put on a lot over the first Prime X, and several testers struggled to hold faster paces in it. Lab testing and two of the reviews rate it well for long runs and marathon-pace sessions, while one US panel called it a step backwards and preferred version 1. Coach's UK review lands in the middle, calling it great fun but priced above legal racers that do the job better. If you want an adidas marathon shoe for race day, the Adios Pro 5 is lighter, cheaper and legal. We'd buy the Prime X 2 for how it feels on long miles, and only once the price has dropped.

The Rocket X 3 is Hoka's do-it-all carbon racing shoe, the leaner, cheaper stablemate to the maximal Cielo X1. Where the Cielo goes big on stack and cushioning, the Rocket X 3 keeps things sharp: a PEBA midsole, a full carbon plate and a 40mm heel that stays legal for racing. At 210g it is not the lightest super shoe on the shelf, but it is versatile in a way the pure marathon rockets are not. This is a race shoe you can genuinely run across distances, from a 5K where you want turnover to a marathon where you want protection late on. We rate it as the sensible carbon racer for runners who want one fast shoe to cover everything rather than a shelf of specialists. At an RRP of 239 pounds it is priced with the elite pack, so you are paying for that flexibility.