Garmin
Forerunner 255 Series
Long battery; but wrist HR tracking is inconsistent.
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I love my 955S. I had the 645 prior and no issues there either.
I had an Apple Watch Series 3 for many years. Then I bought a FR645 to try alongside, just for running. Loved it so much I decided to go full Garmin with a FR745. Loved that watch so much, until I smashed it climbing 🤦♀️ Decided to upgrade to a Fēnix 7S SS because I wanted maps and I clearly needed the sapphire glass. I’ve had the Fēnix maybe 2.5 years now. Recently, I thought I might prefer an Apple Watch as I am now dealing with chronic illness and have not been able to engage in any of my usual sporting/outdoor activities for 6 months. I lasted 3 weeks with an Apple Watch Series 11 before coming back to my Fēnix. I just prefer the MIP display, the battery and the buttons. I don’t really care for smart features. Also the workout screens and maps but obviously not using those much right now. Sold the Apple Watch yesterday. No regrets.
Does all the stuff, predates two major price hikes that didn't come with a lot of value-added. The 65 got a new screen and the 70 got a bunch of new metrics that aren't really actionable. Garmin's comparison tool is pretty good, you can line them up and decide for yourself if the newer ones add anything that's worth it to you. In case you missed it, someone else shouted out the 255 which I think is the best value going in a Garmin watch unless you want maps.
FR645 is what's on my wrist, I like the screen color and contrast. I also own a 6x, but the screen was lacking, although the golf function is much better on the Fenix.
I picked up an FR970 when my FR645 broke late last year. I think a fair bit more advanced than I need but I thought I would treat myself.
I went from F6 to F7 & am now on Venu X1 have loved every single one of them, my colleagues also use Garmin, never heard a bad word against em lol
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.

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Oura - Oura Ring Series

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Apple - Ultra Series

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Garmin - Enduro 3

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Garmin - Fenix 7 Series

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Garmin - Forerunner 255 Series

Ranked #1
Oura - Oura Ring Series