[nextos]

Thanks, I've used Polar HRM since the late 90s, and then switched to Suunto GPS-enabled watches.

But I'd prefer something with a bit more features. Something that can replace very very casual smartphone use. Receive a short call, navigate somewhere. And track my fitness all the time, including HRM w/o band and blood pressure.

[nl]

The VivoActive is pretty nice.

But no mainstream[1] smart watches can replace a phone - they act to supplement it

[1] I think there is an LG watch with a SIM in it, but it has limited availability.

[tdkl]

You need to invent a better battery then.