Excerpt: I bought this for the wife to pair with a new vivosmart (blue as the combos are only in black). Had worked as advertised, no issues in pairing or reading. The band is wide enough to not role, comfortable with the HR monitor snapping into place via jacket style button snaps.
Summary: I bought this to pair with my vivofit a product I love. I've used a timex ironman with a monitor for years and finally decided to replace it with this setup. After 3 months I'm still using my 4 year old timex.