Please take note: This review ultimately ends with a positive impression and I would easily recommend this as a purchase. This review covers my experience with the first watch I ordered, and then the subsequent replacement.FIRST TRY: Wow. What a disappointment. Just received mine in the mail yesterday. Opened it, charged it, synced it to the app and tried it on.So far the most basic features are accurate. Time, weather, Bluetooth calls and messages, notifications. Even the compass and barometer work. Connecting through Bluetooth was fairly seamless. I'm not sure the step counter is all that accurate. It seems... sluggish, to say the least.The biggest problem with this watch is the one that will matter to most anyone who buys it. The sensor/s. Either they aren't strong enough, or they don't work well enough to be accurate. This watch only has one visible sensor that is presumably supposed to perform all the functions that this watch claims to have.I happen to have an Amazfit GTS 2e, and a Mobvoi Ticwatch Pro 3 GPS. Both watches have a total of five sensors, and reliably track heart rate, breathing and other stats. This GTR 3 Pro is still fairly new, and should perform better than it does, but so far... it's not great.I've only been able to get the sensor to work in one of two ways. One is by wearing it with the sensor directly over the underside of my wrist, where you take your pulse. The other is by pressing my finger over the sensor, which clearly is not ideal.The other oddity is that while the watch's weather app works perfectly, AND accurately detects your location, the GPS refuses to work when starting a workout like a simple walk.There's a ton of apps on the watch, and even more available through the Zepp App. But so far, the only fitness feature that works smoothly is the pedometer. It shouldn't be this difficult to get a device to work.I've had a mostly good experience with my Amazfit GTS 2e, so I thought this newer watch would be better by leaps and bounds. So far, the only thing that is better is the design, and the gorgeous display. That's a shame, because right now there are $30 smartwatches on Amazon that perform just as well, or better than this one.Reading through the reviews for Amazfit devices doesn't inspire much confidence. Although many of the devices have four and a half stars, that's usually based on a small number of reviews, and it's usually just over half that give those high marks. A little less than half usually express disappointment for the same issues. Poor performance and accuracy for the one thing these watches are supposed to do. Track health & fitness.I'm going to keep testing this thing for a week. Maybe the watch will perform better once broken in a bit. As of now, I couldn't recommend this watch to anyone. This watch used to be over $200. Now it's a little over $100. Maybe the poor functionality is why.First Update: I've now used this thing for four days. The GPS finally worked on a six mile walk. Unfortunately, because the sensor was not detecting any heart rate, the only data I got from that walk was steps counted, distance, and the speed at which I was walking. I couldn' even get a PAI score because of heart rate tracking being absent.I had to shave a small area of baby fine hairs on my wrist, and reboot the watch before it finally began reading heart rate, and I'm not even sure it was accurate. My Ticwatch usually shows my resting heart rate hovering around 96 BPM. The GTR 3 showed a resting rate of roughly 76 BPM.Even so, tracking of my vitals only lasted for about two hours, and then stopped for no reason. It didn't come back for an entire day, until I restarted the watch once more. I've never had these issues with my Ticwatch, but my Amazfit GTS 2e has been tricky like this. This doesn't speak well for the Amazfit brand.On the positive side, even after four days with all tracking and features turned on, I still have 54% of battery left. Flicking my wrist brings the screen to life with ease. The touch screen can be sluggish or clunky sometimes. I'll do one last update before deciding whether I'll return this thing.Final Update : It dawned on me that I may have just gotten a defective unit. I returned it and received a replacement in three days. Now, everything works perfectly, and then some. The battery life alone is quite extraordinary. Six days straight with all features turned on before I needed to recharge. All tracking feels accurate. Syncing was smooth and without any glitches. Alexa works perfectly.Considering that even premium WearOS smartwatches have had Google Assistant pulled from them, Amazfit and Apple watches are the only option outside of WearOS that offer a useful Assistant app. The display, the battery life, and even the app support on Amazfit devices is better than what WearOS is offering. In my mind, Amazfit is the only true alternative to an Apple Watch.