I had a fitbit one that died after about a year, then I got the Charge HR.
I love them. I like looking at the data and crunching numbers. I am one of those people that will walk back and forth around the coffee table before I go to bed if I am close to my step goals.
Also, it's my watch and heart rate monitor. I can see what activities are really working me, and how much.
I am a student in Health and physical education and more than a few of us have either the flex or charge/ hr. a couple have the oldest one that just tracks steps... can't think of the name.
Anywho. The interface is what won me over. I also have the aria scale. Forgot about that. It's a solid scale, I covered the display so I don't have to look at it every day, but it's tracked. I can't escape reality.