Garmin
Forerunner 255 Series
Long battery; but wrist HR tracking is inconsistent.

Running these analyses costs money. Buy through my links to help keep lights on! I may get a small commission.
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 tracking is inconsistent.

Garmin
Forerunner 955 Series
Best value, clear MIP screen; limited smartwatch features.

Garmin
Fenix 7 Series
Durable, multi-week battery, flashlight; high price, buggy software.
Garmin
Instinct 2 Series
Rugged, solar multi-week battery; bulky, small screen readability issues.

Garmin
Enduro 3
Multi-week solar battery, lightweight; but bulky form factor.

Ranked #1
Oura - Oura Ring Series

Ranked #1
Apple - Ultra Series

Ranked #1
Garmin - Enduro 3

Ranked #1
Garmin - Fenix 7 Series

Ranked #1
Garmin - Forerunner 255 Series

Ranked #1
Oura - Oura Ring Series