Garmin - Fenix 8 Solar (47mm) vs Garmin - Instinct 3 Tactical

These two are nearly even on the Mars Score (58.4 vs 56.8). The decision isn't about overall quality — both clear the bar — it's about which specific trade-offs fit your use.

Pick the Fenix 8 Solar (47mm) if you care most about gps mode and multi-band gps. The biggest gaps in its favor are gps mode, multi-band gps, ecg.

Pick the Instinct 3 Tactical if you care most about smartwatch mode. Its strongest claims are smartwatch mode.

Both ship with comparable solar charging, 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.