I’ve got a Vivosmart, bought the Vivofit for my GF last Christmas as an unsolicited present, fully expecting her to never use it.
She’s really got into it, doing more walking and the fact that she gets rewards through her company health scheme for meeting step targets helps. She’s bought about 10 different coloured bands to use it with too.
I use the vivosmart as a vibrating alarm each morning, bit of step tracking (but not that worried about it), reading phone notifications (e.g. call alerts) and text messages. It also links to ANT+ HR strap and tracks running distances pretty accurately once calibrated. All info gets uploaded to Garmin Connect via my phone. I mainly got it for the phone notifications so I don’t have to dig out a phone from a pocket while road riding to see who is calling/texting.