On Cloudboom Strike 2 vs Salomon S/Lab Phantasm 3 SC:
Which to Choose

Start with how alike these two are, because it matters: both run a full-length carbon plate under springy PEBA foam (On's Helion HF with CloudTec Sphere forefoot pods versus Salomon's optiFOAM+ with the spoon-shaped energyBLADE), both score 6/6 for pace and responsiveness and 2/6 for stability, both are neutral, and both call the marathon their sweet spot with the half marathon close behind. Neither is a daily trainer, a recovery shoe, or a smart pick for slower, heavier-footed running — the tall, narrow geometry on each feels unstable until real pace planted it. The clearest hard difference is weight: the Phantasm 3 SC comes in at roughly 184 g in a men's US 9 against about 200 g for the Cloudboom Strike 2, so the Salomon is the lighter, more stripped-back race slipper, helped by its wind-tunnel-shaped aerodynamic upper (which is genuinely fussy to pull on) versus On's more forgiving open-weave Lenoweave mesh. Drop is a subtler split: Salomon lists a true 6 mm, while On claims 5 mm but measures closer to 3 mm, so the Cloudboom sits lower and flatter and leans harder toward forefoot and midfoot strikers, where its pods and plate return the most. The Salomon's rocker and stiff plate reward a committed heel-to-toe roll and feel smooth and efficiency-focused, where the On's foam reads as a touch livelier and bouncier underfoot. Both carry a race-tuned, protective-but-not-max stack rather than a pillowy one, so cushioning feel is effectively a wash.