Adidas Ultraboost 5X vs Brooks Ghost 17:
Which to Choose

Start with how closely matched they are: both are neutral trainers with no medial post, no plate, and a wide, planted platform that gives each good stability for its category, and both carry a traditional, calf-friendly offset of around 10mm. Stack heights are similarly substantial — roughly 39mm heel / 29mm forefoot on the Ultraboost and 36.5mm / 26.5mm on the Ghost — so neither is low-profile. Weights are close, with the Ghost 17 a touch heavier (about 286g vs the Ultraboost's ~272g in men's sizing); both feel like durable trainers rather than featherweights. The decisive gap is the midsole character. The Ultraboost's Boost TPU foam has a distinctly bouncy, springy rebound you notice immediately — it's lively underfoot but dense, so it can feel sluggish once you try to push the pace, and its effective ceiling sits around 5:30 min/km. The Ghost's nitrogen-infused DNA Loft v3 is the opposite personality: soft but controlled and smooth rather than bouncy, with quiet, even heel-to-toe transitions and a slightly broader fast-end range (down to roughly 4:40 min/km) — the trade-off being it can feel a little flat and lifeless when you surge. Uppers also separate them: the Ultraboost uses a laceless Primeknit sock that hugs the foot for a convenient slip-on feel but runs warm on hot days, whereas the Ghost's laced engineered mesh is more breathable and more accommodating across foot shapes. Finally, versatility differs at the long end — the Ghost is comfortably rated out to the marathon, while the Ultraboost's sweet spot tops out around the half.