Built in GPS, you say? That, with the other capabilities it has without having to use a smartphone, 2-day battery life, and the form factor, this is the closest fit to what I've been looking for in a smart fitness watch. I'll just have to accept that for music I'll need an iPod Shuffle if I value battery life.
Say hello to The Dash by Bragi
http://www.bragi.com
Use that for activity, and Microsoft Band for all day monitoring.
Comes with 4gb storage so you can shove a little music on there. Tracks a whole bunch of info.
Not sure of it HAS to have a connection to a smartphone for fitness tracking though - no idea if it works on its own and syncs later.