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

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From lowest to highest price, the popular ones are Forerunner 70 / 170 / 570 / 970 and Fenix 8 / 8 Pro 70+ have smart watch notifications, support vo2, run, swim, bike, tennis, gym, most other common sports 170+ have WiFi, Garmin Pay 570+ supports triathlon 970+ have maps, have flashlights Fenix 8+ support less common sports like diving, expedition, are made of metal, can be worn in professional settings Fenix 8 Pro has LTE / satellite communication and I think 1 year longer software updates than Fenix 8 I have a Fenix 7 for the looks but I have notifications off and don't use Garmin Pay so a Forerunner 70 probably has all the functions I need 99% of the time
Imo you cannot go wrong at all with the FR70 at this price. Same HR sensor (Elevate 4, no 5 is latest) as the FR265, great battery up to 13 days, same general sports UI and metrics as the FR570/970 and Fenix 8. And like you said: longevity.
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.
Lots of options. Check out the Venu series, Vivofit, and Vivoactive. IMO the value-added aspects of the Forerunner are around running and other aerobic endurance sports. Are those relevant to you?
Forerunner can be a great alternative to Fenix if you're price conscious. Or just last generation Fenix. Do you care about maps?
Forerunner does that stuff too. In general, higher-end Garmins add, they don't take away. Are you serious about any of your sports? Like planning seasons, building for events, that kind of thing?
Changed my mind... I think without an explicit indoor rowing activity profile and VO2max, the extra analysis stuff on the Forerunner won't really work. Not sure if any of the watches have that. I know there are some accepted equations to estimate that stuff, though I think you'd also need a reasonably accurate power meter on your rowing machine. So yeah, Venu or whatever is fine.
My opinion, go with the Forerunner. Check out all the chatter from people moving on from their Apple Watches - I get that some of the newer ones have much better support for running but you say you have an older one. And you're not going to want to carry your phone either. How much running have you done up to now?
The 70 comes with VO2 max for running with the 170 also getting VO2 max for cycling
That's really disappointing. There's not enough to differentiate between the 70, 165 and 170. They could've at least added multi band GPS to the 170 and fully retired the 165.
Yeah, I would have like a budget MIP model.
Yes. Gyroscope and some software features like training readiness, etc.
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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