On Cloudboom Strike 2 vs Adidas Adizero Adios Pro 5:
Which to Choose

Start with how similar they are, because it's striking: both sit on essentially the same platform height — roughly 40 mm heel / 35 mm forefoot on the Strike 2 versus 39 mm / 35 mm on the Adios Pro 5 — both run a low offset (On claims 5 mm but calipers read nearer 3 mm; the Adios is a measured 4 mm), both are rated 5/6 for cushioning and 6/6 for responsiveness, and both put their sweet spot squarely at the marathon held at a hard, sustained effort around 3:00 min/km. The clearest hard-number difference is weight: the Adios Pro 5 is about 175 g in a men's US 9 against roughly 200 g for the standard Strike 2 — a real ~25 g gap you'll feel late in a long race, though On's sprayed LightSpray version narrows it. The other genuine difference is under the foam. The Strike 2 uses a full-length carbon Speedboard paired with CloudTec Sphere forefoot pods, which gives a more aggressive, distinctly rolling toe-off that rewards a strong forefoot or midfoot stride. The Adios Pro 5 swaps a full plate for a carbon-infused EnergyRim — a stiff perimeter ring rather than a continuous board — so its dual-layer Lightstrike Pro (PEBA over ATPU) delivers forward propulsion with gentler edge guidance and a noticeably less aggressive, smoother roll. Fit and upper differ too: On's open-weave Lenoweave mesh is airy over a narrow racing last, while the Adios uses a compressive Lightlock 2.0 upper that locks the midfoot snugly but runs narrow and won't suit wider feet. The Adios is also the newer design of the two.