In reply to PaulHermes:
I've got a charge HR and its great. Insights into steps, calories, sleep and heart rate are surprisingly useful. The novelty has worn off with it and now its just an easy way of gauging my daily allowance of cake/beer, without getting in the way - exactly what you'd want!
The friends leaderboard is a good way of getting you to do a bit more as well - if you get one feel free to add me for additional motivation!