Garmin
Forerunner 255 Series
Long battery; but wrist HR tracking is inconsistent.
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I have a garmin fenix 6 pro and it’s underestimating my calories daily by about 200. According to the watch data and tracking every morsel of food religiously, my weekly deficit is ~2200 calories. I’ve lost between 0.5-0.8kg/week for the last 4 weeks. That means my real deficit is over 3500 calories per week. Every BMR/TDEE calculator does the same, underestimates for me. I barely exercise and get about 8000 steps per day at work. 1400 cals a day, 5ft 3 and currently 149lbs
I personally don’t think you can go wrong with a Garmin. I have a Fenix 6 Pro and have to charge about once a week after running 4 times a week. I’ve had it for going on 3 years too so they definitely last. Doesn’t have the same smart features of say an Apple or Samsung watch but that would be my recommendation
Fenix 6 Pro owner here. Can't upvote this enough. Garmin has excellent battery life, supports a ton of different sports, and is a generally excellent piece of kit.
I use fenix 8 solar, previously had fenix 6 pro and fenix 5 before that. My wife has venue 3. All are excellent. I use HR strap for when I care about HR. Fenix 8 has probably the best sensor from all the farmins, but still a 50$ strap is more accurate. I have no experience with forerunner series. Heard some good stuff, but I dont know what models are better than the others. I would really look at the amazfit rather than an entry level garmin now. $500 amazfit trex is very close to my $1000 fenix.
I started with an Apple Watch and swapped over when the Fenix 6 pro came out, I’m still wearing it, I absolutely want to upgrade to the Fenix 8 amoled but whilst this 6 keeps on going I just can’t justify it, solid watch….
Fenix 6 pro. But looking to change it before spring for something newer and improved battery life.
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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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

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Oura - Oura Ring Series