How the picks were decided
For the music, we went to the source. That means each streaming service's own listing in Garmin's app store, plus the help pages Apple, Spotify, Google and COROS publish themselves. Battery with music comes from the makers' manuals. Everything else comes from testers who measured these exact models and from people living with them. A watch could win only on evidence from more than its maker. Behind this page: we weighed 15 models, with 9 maker manuals among them, and drew on 367 sources this site has kept in full, plus 148 Reddit threads read and summarized rather than kept whole.
Can a Garmin play Apple Music without my phone?
No. Search Garmin's app store for Apple Music and it offers you watch faces. Several are handsome. None of them plays anything. The 170 Music's manual says a Garmin will play your own .mp3 and .m4a files loaded through Garmin Express. Apple Music tracks can't be copied across. Your choices are an Apple Watch, or moving your listening to one of the four services that sync.
Do I need Spotify Premium for Spotify on a running watch?
Yes. Spotify's Garmin listing says it requires Premium. Spotify's Apple Watch page says the same for downloads and streaming without the phone. Spotify's help page adds that downloads have to reconnect to the internet at least once a month. Amazon is the kinder one: Prime members get the All-Access Playlists offline without paying for Unlimited.
Will the battery last a marathon with music playing?
On every Garmin pick, by Garmin's own figures, yes. The shortest is the 170 Music's 7.5 hours of GPS-only with music. For a 50K or a long trail day with earbuds in, we'd want the 970's 14 hours. Garmin's own manuals list switching off the always-on screen among the first ways to save battery.
Why do my earbuds keep cutting out on a run?
Every Garmin music watch here that has been out long enough to gather owner reports has its share of these complaints. The brand-new Enduro 4 has none yet. The music is fine until an activity starts, and then it stutters. A watch that misbehaves with one pair of earbuds is often fine with another. Garmin hasn't named a cause. The 170 Music's manual asks you to keep your body out of the path between the watch and the earbud that holds the antenna. It suggests wearing the watch on the same side as that earbud, or simply switching wrists. It also says to put the watch on a silicone strap if it's on metal or leather.