Garmin
Forerunner 255 Series
Long battery, but wrist HR often inaccurate.

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Same reason + price increases and EOL of previous models as soon as new one comes out: migrated from Fenix 7s Solar to Coros Pace 3. Actually everything is fine, the only annoying thing is the device design itself: after Fenix - Coros looks sporty and cheap. But this is not their fault: I just wanted to try the cheapest model they had, so nothing really stops from upgrading premium-to-premium: I should have chosend Apex 4 :) About lots of training data: yes and no; it's sometimes motivating to recheck your data from several years ago, but how often do you REALLY do that? In 1 month your watch in other ecosystem will also collect the data and you will have the current condition as a starting point. By the way for example Coros has the importing option, so you can just import all the HR and other data from Garmin. But from my experience - better just start fresh, the data will be more proper (probably there are some missing parameters..).
Coros pace 3, super solid and probably on sale with the pace 4 coming out.
coros pace 3 has always gotten me at about 26.4 miles for a marathon, which isn't too far off, and I just look at the elapsed time versus the course markers to predict when I'll finish
Coros Pace 2 or Pace 3. Very satisfied with this watch
Go for Coros Pace 3
I love my coros, I still just use the pace 3. Super competitively priced and the app is miles better than anything else I’ve used
Garmin
Forerunner 255 Series
Long battery, but wrist HR often inaccurate.

Garmin
Forerunner 955 Series
Endurance battery, value king, but clunky UI.

Garmin
Fenix 7 Series
Rugged, long battery, maps, but HR and software can struggle.

Garmin
Enduro 3
Unrivaled multi-week battery, solar-charged, but bulky.

Garmin
Forerunner 965
Lightweight, vibrant AMOLED, maps, but wrist HR and swim issues.

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Garmin - Fenix 7 Series

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Garmin - Fenix 7 Series

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Garmin - Forerunner 255 Series

Ranked #1
Oura - Oura Ring Series