Mizuno Wave Horizon 8 vs New Balance Fresh Foam X 860v15:
Which to Choose

Start with how alike they are: both run an 8mm drop, both sit high on soft foam (the Horizon 8 at roughly 42mm heel / 34mm forefoot, the 860v15 at about 40mm / 32mm), both lean on a composite plate rather than carbon, and both weigh in on the heavy side for a trainer — around 323g for the Horizon 8 and 332g for the 860v15 in a men's US 9. Neither wants to run fast; the foam absorbs far more than it returns, so you get calm and protection instead of pop. The meaningful split is in the character of the ride and the stability approach. Mizuno's ENERZY foam feels soft but composed, and its signature nylon Wave plate plus a wide base actively organizes each landing — the result is a more structured, planted feel that stays smooth and controlled as you tire, which is why its sweet spot is the marathon and long training runs. New Balance's single-density Fresh Foam X is softer and more pillowy underfoot, guided gently by a full-length medially-wedged plastic Stability Plane rather than a firm post or rigid plate; it's a cushier, more forgiving ride that can feel slightly floaty when you slow right down, and it's happiest at half-marathon distance. Fit and upper are the other decider: the Horizon 8's engineered mesh is secure and breathable, while the 860v15's denser synthetic mesh locks the midfoot and heel down well but runs warm on hot days. In short, the Mizuno is the more structured, guided, long-haul-stable option; the New Balance is the softer, gentler, more cushion-forward one.