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

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I have a Garmin 945 that's going on 6 years, following a Garmin 910 that still worked when I retired it after 9 years. Right now the battery lasts ~6 days, down from ~2 weeks when I bought it. One button is starting to have intermittent contact issues. On the water front, these are triathlon watches and are designed for swimming. I have replaced each band once, and I use a quick-release leather band for daily wear and a quick-release silicon band for swimming. My next one will probably be either the 955 or 970, once the button gives out.
I don't know if there's a "correct" way, but I count the rest time in the same way I count the rest during a run, bike or strength workout--it's all part of the total time for the session. The older Garmins, like the 910x, used to just lap as a split where the newer ones from at least the 935 on switched to a rest with the lap button press which I always found annoying since you couldn't split a longer interval nicely that way without fumbling with a double tap. Ended up just using my 910xt for swimming to also help save the barometer in my 935 lol. As another commenter said, once I got the FORM goggles I didn't have to worry about that anymore. 😀
I don't know if there's a "correct" way, but I count the rest time in the same way I count the rest during a run, bike or strength workout--it's all part of the total time for the session. The older Garmins, like the 910x, used to just lap as a split where the newer ones from at least the 935 on switched to a rest with the lap button press which I always found annoying since you couldn't split a longer interval nicely that way without fumbling with a double tap. Ended up just using my 910xt for swimming to also help save the barometer in my 935 lol. As another commenter said, once I got the FORM goggles I didn't have to worry about that anymore. 😀
Was GARMIN for many years, starting with Forerunner 910XT and progressing to Fenix 5Pro Saphire. Did last Tri event in 2019 and ended up switching to AWU when it first was released. I have no regrets, if I ever go back to Tri will probably use another GARMIN for racing/training but keep AWU as daily driver.
Nice. Was going to ring in with my 910XT, but you win.
You buy a Garmin for what it does today, not for what it may or may not do in a year with some maybe-happening update. As opposed to typical (real?) smart watches, a Garmin will keep working for years and will be compatible with the app even if it is not receiving further updates to its software. I can go for a run with my 15 year old 910XT today stick the ANT stick on my computer and upload all the data to the app with all the functionality the watch had the day I got it. I can probably do that even with my 18 year old 305 (I haven't tried in a while, but I would expect it to work). So, buy something that satisfies your needs today. It will keep doing it's job for its lifetime. If you develop additional needs, well then you can consider an upgrade.
I can remember running before GPS running watches came about, but I wore my candybar garmin for years! Wish I wouldn't have given it away, because it was still working great when I decided to downgrade to a smaller/newer model. I usually keep mine until they break or die. I spend enough on shoes every year, I'd hate to have to buy $500 watches more often than I have to. My current Garmin is going on 7 years. Still works great, still wear it as my daily and running watch. Replaced the band a couple of times, but still holds a great charge.
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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