Garmin Fenix 8 wins for athletes needing 29-day solar battery, dive capabilities, and flashlight (per Garmin specs) while Apple Watch Series 10 provides superior value at $399 with sleep apnea detection and faster charging (per Apple specs). The $600 price gap makes Apple the pick for most users but Garmin dominates extreme training scenarios. This is a clear split by use case rather than a clo...