Garmin
Forerunner 255 Series
Long battery, but wrist HR often inaccurate.
Running these analyses costs money. Buy through my links to help keep lights on! I may get a small commission.
+1 on the Oura ring. I know he said no subscription. But I went on the same quest last year and there simply wasn’t anything worth having that didn’t have the subscription model. And I think $59/year is fair for the services I get. I have a white gold wedding band and just got a silver Oura ring and switched it out. It’s now my wedding ring that I was wearing anyway, and it gives me all the information I needed. The app is crazy intuitive, even noticing when you’re displaying signs of being sick. It knows before I do, gives me a notice, and reduces my activity goal for the day based on it. I wear a Garmin Forerunner 55 for runs and workouts and my nice watches the rest of the time. I’m a big fan.
I've had my ring for years, since Oura 2. I bought for sleep and love it for sleep. I just upgraded to the 4 because my battery was dying quickly. Customer service is great. Movement tracking throughout day is nice, but i use my Garmin for workout tracking. I have an eight sleep mattress and don't even look at the sleep stats on it because oura is my main tool. The relaxed time or what's called on the ring is very telling for me. If I'm off or having some bad days I look at for sure my green relaxed time or whatever is down. The ring data matches how I feel most or a lot of times. I love it. It's my sidekick.
I have Gen 2 that is still working after 7 years and Gen 3 going on 4 years. Never had any issues. I keep the ring in flight-mode 24/7. Only wear it at night when it gathers all the important data. No benefits wearing it in the daytime. Will only shorten the batteries longevity.
An oura ring. Sorry not a watch, but helps me stay consistent and motivated. I've worn one now for 4 years or more (started with gen2, now on gen3), and I love how it keeps me consistent, helps me understand what influences my resilience and sleep, and also isn't a watch as I don't wear any other jewlery or watches when I work out or sleep.
When I first got my Oura (back when v2 first came out?) they said that you had to wear it for at least a week (maybe a month??) until it could calibrate correctly to your body. Just saying that 1 week might not be sufficient to track any kind of accuracy (in *any* product). However... A week should be sufficient time to see if the device can be continually worn *comfortably*. If they're both comfy, I say stick with them for at least a month and then start seeing how the data compares. Hell, throw in a third device for good measure! (Pun intended.) And as someone else said, they may just classify the sleep stages differently too. So it might be better to look for overall trends in your sleep/activity habits, rather than focus on the specific numbers themselves. Good luck and thank you for sharing your experience!
If you can get one. I’ve had such an awful purchasing experience that I’m pretty much giving up buying it. I really liked the gen 2 but for the cost and the battery losing charge so quickly coupled with the app. I don’t see it worth the money. If their customer and Amazon partnership was more human and could resolve an easy order issue I would recommend it. But amazons sent me the wrong size and now my FSA funds are tied up for 14 days since they can’t do a simple size exchange.
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.

Ranked #1
Oura - Oura Ring Series

Ranked #1
Apple - Ultra Series

Ranked #1
Garmin - Fenix 7 Series

Ranked #1
Garmin - Fenix 7 Series

Ranked #1
Garmin - Forerunner 255 Series

Ranked #1
Oura - Oura Ring Series