My experience trying to use Strava live segments in the last 6+ months has been that this feature fails to work correctly far more often than it succeeds. My area has tons of Strava running segments on all popular trails. That is a perfect way to challenge myself and track performance improvement over time. Strava live segment tracking is a feature exclusive to only a few top Garmin models. The only problem is that it basically doesn't work most of the time unless the terrain is completely open. Sooner or later Fenix drops off a segment - usually that happens in a tight turn. If I look at the map at that time I can see myself right on top of segment, so it is not clear why exactly segment gets dropped. I see the same kind of issues when tracking courses, however in a case of tracking a course the watch can usually quickly rejoin the dropped course. But in a case of segment, once it is dropped the tracking is aborted.
For example today I followed a long 16 mile segment which also happens to be a popular local FKT route (https://www.strava.com/segments/1028327). Sure enough, after about 5 miles, for no apparent reason my watch had dropped off that segment. But most of the time Fenix can't stay on a segment even that long.
Just to be clear, it isn't a problem with the GPS accuracy. Strava has no problem matching those segments afterwards when a run is synced to Strava. It is just the live tracking during activity that is broken. And another comment is that tracking the same segments used to work more reliable in the past. One year ago my Fenix could finish most segment and only failed occasionally. But now it fails on trail running segments most of the time, so basically the feature is no longer useful for me.
