Garmin created the best alternative to the Apple Watch when it came out with the Vivoactive 3 Music. For 2019, has Garmin updated that device with the Vivoactive 4 series, which includes the 45mm Vivoactive 4 and the 40mm Vivoactive 4s. Minor hardware changes accompany equally minor smartwatch software changes in this device, but that's because new fitness features steal the show.
Garmin added a ton of fitness improvements to this watch, including optional all-day pulse ox measurements, hydration tracking, new breathing exercises (that don't suck), new custom workouts, on-screen animations, and more. Unsurprisingly, all those improvements add up to the Vivoactive 4's $349 starting price, which is at least $100 more than what the Vivoactive 3 Music goes for nowadays.
Those features add a lot of value and push the Vivoactive 4 ahead of even the Apple Watch in terms of fitness, but I still have a soft spot for the Vivoactive 3 series—and plenty of happy users may skip this upgrade.