It's nice to see that they have an API to export your data too.
Heart rate monitoring is a bit of a sham, if you're looking to use it during exercise. It's designed to gather more of an average rate throughout the day than give an accurate reading while you're exercising.
The Basis tracks sleep without you having to put it in sleep mode (e.g jawbone UP), which is pretty handy.
They recently added some features that attempt to recognize walking/running/biking automatically ("BodyIQ" is the marketing name). I found it oddly useful for seeing how long it took me to walk places.
Coolest feature: if you rotate your wrist quickly (as you would to look at a watch), the face lights up automatically.
Bluetooth sync works well with Android, pretty useless with iPhone (you have to keep the app open and phone awake or it tends to be flaky).
Basically I like the watch, but for weird reasons - the health tracking isn't really that much better than others, but there are little surprises here and there that make it useful for me. YMMV, and I really don't think seeing how many steps you took in a day will ever be life-changing for anyone.
http://tomsalmon.eu/2013/12/data-download-and-nagios-plugin-...
They focused on gamification and achievements you can unlock ("slept full 8 hours" etc). However it lacks any wireless connectivity, so you need to plug to your computer to download data every day.
I thought it's the most interesting of all smart devices, but I was looking for next gen which hopefully would be wireless and smaller.
Recent ones sync automatically over bluetooth with an smartphone
I regularly sync mine with my iPhone.