I have similar thoughts as OP (though I now use a Series 7 and have few to no issues with GPS now) - the Garmin Fenix 5 or Coros Pace 2 are pretty great. Ive done trail ultra's, road halfs, mixed bike races, city to city tours and everything in between with both. Coros doesnt integrate with as many things as I would like.
Garmin's entire line-up is pretty great. They focus on things that matter: honest GPS measurements and battery life being at the top of the list. I really like some of the new Tactix 7 features, like the ability to remember the route but forget the geo coordinates.
