Am I the only one who's concerned if a large corporation wants to tell me I sleep better than 93% of the people? Or how my heart rate is doing during sex workouts? Especially as a Bitcoin user, you should really care more about privacy.
They're just a gimmick. Tried the heartbeat test and this smart band thing always got it wrong (at least the cheap one).
That being said, notifications via e-mail is probably safer.
Without a doubt, it is an elegance to have that device, in addition to that it attracts attention, modern, with many features, it is not so expensive, anyone can ask what it is, how it works and they will surely want to enter the forum and learn more about Bitcoin and the technology.
I'd rather stay low than being put in a spotlight where everyone can see that I have an account in this forum. Don't want them to $5-wrench me.