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

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Any amazfit works here. I bought a BIP 3 pro used off amazon for like $30 to see if I liked it (just needed notifications for work). Worked great and bought a GTR. Handed it down to my MIL and she still uses it
I'm excited to try one for the first time. My amazefit bip3 pro was good until I put it in my pocket and it broke where the straps attach. I started using my wife's Garmin (she didn't like it) and I hate the UI for it. Other than that it's great. I'm hoping the UI is better on the pebble. The battery life sounds amazing too.
Maybe a fitness tracker is better? Xiaomi bands are very small. Or if you need GPS an amazfit bip is a lot less chunky than most watches.
Kinda regretting getting the round early. I'm used to the square Bip and this feels sexy.
Pixel 10 Pro with Amazfit Bip watch. Reason - dirt cheap "smartwatch" that sends me notifications, that's about it. I don't need anything fancy with the smartwatch
Amazfit. I think the worst you'll get is 5-7 days with everything enabled, most will do 10+, and some 20+ days with a mix of features enabled. They all have really good screens, the newer ones have better features like enhanced notifications with images, ability to reply to messages with voice or typing, built in AI assistant The Active 2 is often on sale, there's also the Active 2 Premium which adds sapphire glass screen and NFC for contactless payments, then there's the Balance and Balance 2 for basically every feature with a bigger screen and battery, they do the Active 2 square if you prefer that, they also do the Bip range for cheaper square ones. It does depend on what features you want, they aren't WearOS so you can't get the same range of 3rd party apps and watch faces, but there's still quite a few out there. Personally I prefer them as they run smoothly, have good battery, and are generally smaller than WearOS Watches.
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