I have had a Fitbit Charge 2 for about a year. No issues with the band, operation or battery life.
I like tracking my steps, it reminds me to get off my butt & move. I also like the sleep tracker. I developed some poor sleep habits in my w*king years (from stress, worry, and middle-of-the-night support calls), and I am trying to improve in that area now that I am retired.
It does have some quirks, though.
When I use the snowblower, it thinks I have been bicycling
. For some reason it does not do this when I push a shopping cart,or push my Mom in a wheelchair. It somehow knows I am walking then.
The sleep tracker sometimes does not work - I think if the band slips down on my wrist and is not tight enough, it can't read my heart rate. So there is an occasional sleepless night recorded when I actually slept just fine. I went to see a movie in a theater a couple weeks back, and it recorded a two-hour nap during that time.
I stopped wearing a wristwatch years ago, and was afraid this would be uncomfortable, but it's not. And now when I look at my wrist to check the time, I actually see the time (I never quite lost the habit of looking at my wrist when I stopped wearing a watch).
It seems to record stairs most of the time correctly. I read somewhere that it looks for a 10 foot change in elevation. So if I remember to raise my arm up when I get to the top of the stairs, it usually works, although sometimes it works without my doing that. (My ceilings are 8 feet).
Mine is supposed to be water resistant, and so far has done OK if I forget and wear it into the shower - I've removed it and towel-dried it pretty quickly the few times that's happened.
When I have it off for charging or showering, I usually clean it with some rubbing alcohol. My only complaint about the band (the original silicone one) is that it's fussy to buckle and get that little bump on the underside of the slide to fit into one of the holes on the band.
I have a few minor scratches on the face apparently from hitting it against something, but it does not affect anything. <edit - the Fitbit's face, not my face>
My main complaint is I seem to have a (hopefully-not-permanent) divot in my arm from the underside of the unit.