Fitbit

I also have the Charge HR ~ love it. A friend lost her Charge (the next one down) while out on a hike, the company sent her a new one for
free, she sold it to a work mate and put in the extra $ to replace it with the HR because the clasp is better...

Whole day, but my workouts consist of resistance bands and walking. If you spend a lot of time doing non-standard state cardio, it may be less accurate.

I got the fitbit flex 5 days ago. Its battery is draining about ×2 -3 faster than it should so fitbit are sending me a replacement one. It has fulfilled its purpose in providing me with some motivation to be more active. I like how it tracks my sleep. But i agree with the post that doubts the accuracy of steps it counts

I have a Charge HR and love it. I have previously had a Flex which I also loved, but lost it without trace after only 3 months :-( Charge HR (not regular Charge) has a proper watch-style buckle. I find it very motivational, but I'm a data-hungry scientist who loves setting small achievable goals. I have just given a Charge HR to my DD for her 11th birthday and she's already showing the same tendancies as me :-P

Fitbit models, and other wearable tech do vary in their sensitivity. The cheaper products only use arm movements to estimate the distance you've travelled or steps taken, and that of course isn't very accurate. You have to tell the Fitbit app if you are wearing it on your dominant or non-dominant wrist (non-dominant is recommended) so that it can compensate. But I'm a right-handed violinist who finds Fitbit thinks I've run a marathon when I've played for an hour at someone's wedding!!! Unfortunately I rely on the digital clock of my Charge HR to know when my gig time is up and I can go home, so I'm not going to take it off any time soon! My old Flex used to get excited when I pushed wobbly supermarket trollies, but was fine with new trollies. Apparently some models fall into sleep mode too if you sit at your computer for too long etc.

If you want real accuracy then you have to choose a high-end version that is GPS enabled, although you must be going for that if you're talking about the 'watch' (do you mean Fitbit Blaze?). You probably can't have the GPS tracker operating all the time without flattening the battery after 8 hours (I'm guessing) but you're also unlikely to be considering a $300+ device as a means to count steps alone.

I'm finally running regularly, and finding that I'm losing interest in trying to reach 10,000 steps daily as a consequence, because I know I'm burning far more calories in 3 reasonable runs each week. I'm now more interested in the heart rate monitoring of the Fitbit, which clearly shows my lack of fitness when compared to my various running apps' estimate of calories burned based on my age, height and weight. A device that is watching your HR will give you a more accurate calorie burn, and I MUCH prefer this optical HR monitor thing (regardless of the +/- accuracy) to wearing a HR belt under my bra. I love the automatic sleep monitoring, whereas the Fitbit Flex needs to be put into sleep mode manually (very easy to forget to tap it repeatedly as you're dropping off to sleep). I like the auto exercise tracking, but had to turn some of the things off after it thought I'd hiked 1200 km in 14 hours with an astonishing number of steps (and rewarded me with an 'over-achiever badge') :-O when we drove it... the vibrations on the steering wheel must've done it. I now only have it auto-recognising running and walking to avoid these mistakes. If you do other kinds of exercise then you can use its stop watch mode which is manual input of a workout. It will just monitor your HR etc for the duration that you have it operating, and save it as exercise. I love it :-) But since I've realised that I'm slowly becoming a runner, I'm interested in something that is properly GPS enabled. My Charge HR can use my phone's GPS to be more accurate when calculating distance, but it needs my phone to be there of course. I'm now wanting something specific for runners so that I don't have to obsess over all these apps throwing data at me and can have a simple watch face saying New PB!

There is some evidence that wearable tech has a more negative effect than positive, population-wide. I love mine and find it motivational, so I guess personality is key. It was really good to see a baseline of what my daily activity was really like, and rather than be put-off (as I could have been, easily) I got excited about meeting goals and would go out onto our steep road at 8pm to walk the 1500 steps left until my Fitbit vibrated and told me I'm awesome LOL! If you're more advanced than this then I'm sure you'll find the high-end products meet your needs if you're data-hungry and not demotivated by numbers that aren't as good as you hoped.