I've had a Fitbit Alta HR for 5-6 years now, and while I'm surprised it's lasted this long, it is on its way out. It only keeps a charge for a few days and it doesn't seem to stay connected to the phone, sometimes goes several days or weeks without syncing. I am not sure what could possibly be causing that but it's pretty inconvenient when I realize it isn't syncing anymore. So it was time to go.
I'd heard of Amazfit a few times but didn't pay too much attention to their offerings and price and I initially was very skeptical... A device that offers more (on paper, anyway) than the Fitbit for a third of the cost. I have had an Amazfit Band 5 (otherwise known as the Xiaomi Mi Band 5) for several weeks now and it's excellent. I get 10+ days out of the battery, the band is comfortable, the size is perfect, the screen is quite readable even in sunlight, etc. I do question the Zepp software a bit in that it shows it'll do Blood Oxygen, and you can tell that it's doing it at night (red LED on constantly) but the data never shows up anywhere. But for other things like steps, stress, heart rate, etc, it seemed to align very well with my Fitbit.
Another thing I question is the sleep analysis; it doesn't seem to match up with my Fitbit, but when I looked closely a few nights when I wore the Band 5, Fitbit, and a WearOS watch running Sleep as Android, none of them really matched up that great, but the Band 5 in particular never seems to show deep sleep and rarely shows any kind of sleep cycles. I suspect this could be tweaked in software but it's been out for a while so I have no expectation this will happen.
The Amazfit also has a pretty large community of people who make custom faces and third-party applications that can replace Zepp as the phone software. I've tried a few of the third-party apps and I found them clunky and unreliable and when they were installed data wasn't getting reliably stored, no heart rate, no steps, etc, but I plan on trying them again sometime in the future as they did have more features and tweaks.
I think if I ever get another smartwatch or a bigger fitness band, I will start at Amazfit and see what fits my needs.
(Nearly) One Year of ownership update
I've used this band for almost a year and wanted to post some updates.
First is that I'm utterly amazed that the screen still looks brand new. I'm pretty careful with not banging my arm into stuff, but it happens, and I don't recall seeing the band specify any particular scratch resistance, but it still looks absolutely perfect which is amazing to me. My Fitbit was starting to look dinged and scratched within 6 months like it was made out of really soft plastic. I am honestly not sure what material the Amazfit Band 5 is but it must be a hardened glass. And overall the device itself is still in great condition, with no issues with the rubber band, fit, etc. I honestly expected some wear, tear, etc, by this point so I'm very impressed.
The software has continuously gotten updates which are great to see, yes sometimes a feature is added and a feature is removed, moved, or broken, that happens in all software, but by and large, the software has been improved multiple times over the past year.
SpO2 still does not give any kind of "continuous" reading that I've seen, even though the software has always implied that it does. If left enabled it seems to give a little more data in the Sleep section, but no specific SpO2 information. I'd really like to know what my oxygen levels are throughout the day, especially in this day and age of that being an indicator of potentially having an infection and a high-level indicator of health. Manual readings work fine, but I would have really liked to have seen automatic periodic measurements when the band is set to do so and the ability to review those results like the other measurements the band does.
And one bug that I've seen twice but happens rarely enough that I didn't experiment with it much; the watch strangely doesn't immediately update on DST time changes. In the Fall of 2021, I noticed this but when I went to look into it the band had already updated, even though it was late morning or so when I was looking so in theory it should have happened 7+ hours prior. Spring of 2022 I also noticed the same; no automatic update. This time about 3 in the afternoon I disabled Bluetooth on my phone momentarily and then the time was immediately updated on the band, so again, 13 or so hours after it should have automatically updated. So not the end of the world, just a very strange bug to go overlooked.
And one more issue that I wish they'd improve is the integration with other apps and authorization/token timeouts. For example Google Fit, I'm not sure yet of the exact timeframe but about every 90 days it seems like the authorization expires and it quietly stops sending data to Fit. I only happen to notice it and have to go into the Zepp app and go through the process of re-authorizing it. The process is easy, and it seems to sync all the data once it's done, but it's still silly that it does not at least warn me when this happens. I made a note of the last time it seemed to time-out on me so next time it happens I'll see if there's a pattern, however, it's happened to me at least 3 times in the last year that I can recall.
A quick note about other Amazfit devices
While the Band 5 is an amazing deal that works great, especially for the price, Amazfit has a bad tendency to put out as many devices as they can and not support them very well and have mediocre sensors in them. At the typical price of $35 for the Band 5 this can mostly be forgiven, but they are attempting to sell the TRex 2 for $250 which is more expensive than the previous model but with nearly no improvements. I had considered getting one but with the price and the heart rate sensor performance I am no longer interested. I'll see how the Band 7 looks when it comes out soon, it may be a decent device to upgrade to.