I borrowed my Dad's Fitbit Ultra for a walking challenge a few months ago, and found the thing pretty underwhelming. It had connection problems (to fitbit's credit, they sent me a new base station at no charge,) occasionally reset several hours before midnight, and started cracking apart at the seams. (They discontinued the Ultra, perhaps for that reason. Maybe the others are better.)
I needed it to track 1000 steps a day for 3 months, and it did do that, but I just didn't see the point after the competition. I know on what days I'm putting in the exercise, having the Fitbit just to confirm that to me didn't seem worth much, especially considering the questions about it's accuracy. I haven't really bothered with it since. My Dad never asked for it back, so I don't think he liked it either.