Apple - Watch Ultra 3 vs Xiaomi - Watch S4

These two are nearly even on the Mars Score (65.3 vs 63.9). The decision isn't about overall quality — both clear the bar — it's about which specific trade-offs fit your use.

Pick the Watch Ultra 3 if the display is what you stare at all day — refresh rate, brightness, or sharpness is where the difference will be most visible. The biggest gaps in its favor are display size, peak brightness, water resistance.

Pick the Watch S4 if your top frustration with your current device is running out of charge before the day ends — endurance is the lead spec here. Its strongest claims are battery life, weight.

Both ship with comparable ecg, cellular, spo2, 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.