Insta360 - Ace Pro 2 vs DJI - Osmo Action 4

These two are evenly matched on the broad strokes, with the decision sitting on which individual spec advantages weigh more for your use.

Pick the Ace Pro 2 if you care most about max video. The biggest gaps in its favor are max video.

Pick the Osmo Action 4 if you care most about waterproof depth. Its strongest claims are waterproof depth.

Both ship with comparable max 4k fps, stabilization, horizon lock, so those specs don't separate the two — focus on the differences below.

Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity tells you both are well-rounded; the differences are about trade-offs, not quality.