Saucony Kinvara Pro vs Asics Magic Speed 4:
Which to Choose

The clearest split is foam and heft. The Kinvara Pro stacks a PEBA-based PWRRUN PB top layer over a firmer PWRRUN base, giving a tall, plush, genuinely resilient ride that protects over long miles—its cushioning rates a full 6/6 and the rebound is lively but smooth rather than snappy, the plate doing gentle work rather than flinging you forward. The Magic Speed 4 instead uses FF Blast Plus Eco, an EVA-based foam, so it feels moderately firm with a springy pop (5/6 cushioning); rebound is strong but stops short of a true superfoam, and transitions are quicker and more connected the harder you push. Weight reinforces that character: the Kinvara Pro lands around 269g in a men's US 9, while the Magic Speed 4 is noticeably lighter at roughly 238g, which you feel as more eagerness to turn over at faster paces. Drop is close—8mm on the Kinvara, 7mm on the Magic Speed—so neither changes your gearing much. Stability is a wash: both are neutral 3/6 with no posts, the Kinvara leaning on a tall, wide platform that can feel a touch tippy at slow jogging speeds, the Magic Speed sitting on a firmer but only moderately wide base that asks for attention in hard corners. Use case is where they diverge again: the Kinvara Pro is built for the half and full, with the marathon as its true sweet spot, whereas the Magic Speed 4 stretches from 10K up through the marathon and is happiest at the half—more of a do-everything fast shoe, less of a dedicated long-haul cruiser.