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

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I recently switched from a Coros Pace 2 to a Garmin Fenix 7 Pro Saphire Solar and absolutely love it. Feels much more substantial than the Coros and battery life is awesome. The Coros battery life had severely degraded over the last 6 months.
do you like hiking at all? The fenix series as well as the Forerunner 965 IIRC have some pretty awesome integrations with AllTrails...I'm also a huge proponent of buying used on Facebook...it takes some research, but the used market is solid for these devices and a great way to start...I've bought 6 watches(family of 4) only one was new(fenix 7 pro saphire titanium) as it was a great new price during some sort of seasonal sale... :) I couldn't recommend the garmins more over any apple or fitbit devices...tjeu are great watches and battery life measured in days instead of hours is a luxury you will also appreciate....On my fenix 7, I love the flash light...totally unexpected top 3 feature. :)
i sleep with it everyday (47mm). dont really notice, but i swapped out original silicone band with nylon band on day one
Had a 265, moved to a 47mm Fenix 7 Pro because I wanted full mapping since I started trail running and MIP display and didn't care about potential new features. Yes, the Fenix units weigh more, but a good chunk of that weight comes from the stock chonky silicone straps. The difference between case-only on my kitchen scale was \~10-13g if I remember correctly. When running, I definitely noticed the additional swing weight on my wrist with the F7 on stock silicone, but don't really notice it now that I have it on a nylon band.
If you are on a budget the two best options IMO are fenix 7 pro ss with MIP or epix pro gen 2 with AMOLED. I just went fenix 6 standard to epix pro gen 2. It is definitely nicer. But not a game changer. Fenix 6 pace pro and garmin training plans for running. Do you have maps, garmin pay, and training plans on the 5?
Fenix 7ss. But also have an edge bike computer in the whole Garmin ecosystem. Swimming has been great and gets the job done. Running is pretty straightforward with any Garmin watch. Can’t speak to an oura ring. Just a chest or arm HRM.
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