I upgraded from a fossil watch 5 Carlyle that I absolutely loved everything about except it's one day battery life. After two years, it started locking up and having battery issues. I have a Samsung phone and was originally going to get the galaxy watch 6 but saw this oneplus as a unique alternative. Got it on prime day plus discover rewards points for a great deal.Battery - let's start here. This thing is amazing! I wore it 4 days straight (sleeping and all) on a camping trip in battery save mode and it still had 64% left after 4 days! Now we have starlink when camping so my ohobe was still getting alerts and notifications the whole time. Battery saver mode still gives you all the notifications in addition to the health functions like heartbeat and sleep tracking. The fossil disables pretty much all those things in battery saver. Youose "smart" features like battery monitor (strangely), and the ability to disable notifications on phone when wearing the watch (also a strange omission). In smart mode with tilt to wake, and with sleep tracking on (but blood O2 tracking off) I can get 4 days easy.I was afraid this watch would be too big since it's 47mm but it's actually a tick thinner than the fossil gen 5 and I can't really tell that it's any heavier or larger on my wrist. I did purchase the dark metal bracelet style band as I prefer that to the silicone bands since my wrists swell in the heat and sweat which is uncomfortable with the rubber band style. Now the kicker is on my fossil gen 5, I had GPS disabled, heart rate tracking disabled, always on screen ON, and was lucky to get 14 hours of use. This oneplus 2 watch I run with all the sensors on, but use tilt to wake because it's soo dang fast to show the time! And it still goes 4 days, maybe more depending on how many notifications you get, and I get a ton.The new android watch OS is very fast and the buttons on the watch have good feedback. Sapphire screen is very smooth, but I worry about cracking it. I used a tempered glass protector on my fossil and replaced it wvey few months because it would chip on the edges. I never used it without the protector, so can't speak to it's durability or if the screen protectors just stuck out a bit higher and we're prone to catching and cracking?There doesn't seem to be much in the way of decent protectors for this watch. The full watch covers collect moisture and look cheap, the glass protectors don't come to the edge fully and ruin the smooth look and feel of this awesome watch.As far as extras, there is a barometric sensor that will tell you approx elevation. It only shows in meters which is dumb but maybe they'll fix that in the next update. It will measure blood oxygen while you sleep to do snore tracking. But using it will cut your battery life in half. So I only use it once in a while to see how bad I'm snoring.There are lots of watch faces and many have customizable widgets you can edit what they display. I wanted a simple large digital display like I had on my fossil nut have settled for the one pictured. I can access stop watch and countdown timer from the screen, as well as view heart rate, step counter, battery level, and outside temperature (awuired through the weather app, not a sensor on the watch).The Ohealth app is the interface app for Android. It will allow you to view the sleep info and exercise data but you can also view those right on the watch. A double press of the lower button activated Google pay, and it works flawlessly and at a greater distance than my fossil would. If the biggest complaint people have about this watch is that it's "large" and that the rotating crown on the top button doesn't do anything, if say this watch is 98% perfect. I wish they made a slightly smaller version in different colors so my wife could upgrade as well. Maybe the 2R will have those options. The premium feel of this stainless body unit is awesome though, and it's really not heavy at all if you're used to wearing a premium on smart watch or fossil smart watch.As far as charging goes, you just use a little usb C powered square Puck with only one charging orientation. I wish there were a third party stand option like I used for my Fossil watch. I see some on Etsy so maybe more will be hitting the market soon? That's actually my biggest complaint is lack of accessories as compared to fossil or Samsung.