Well of course I finally bought one a week ago.. And dammit i kinda like it. I usually don't like a square watch full stop but i'm getting used that. I thought it would be totally pointless to control music when usually the phone is in my hand anyway .. But as i found on Friday night it's handy to control the music when the phone is by the bose speaker thingy across the room and voice recognition works really well even for sottish english .. "Play some bagpipe music"
And i can respond pretty well to msg or whatsapp using voice.
Being an admin of a FB group of 18k members i get a lot of messages! Having a quick look on the wrist is pretty good compared to the phone.
The health stuff - unsure, it's probably fine for general walking around but it's not for proper running/cycling. No Ant+ just like the phone and you need the phone for GPS.. Today while out cycling it measured my heart rate every ten minutes.. My garmin HRM monitors constantly and the difference in numbers is night and day . After a particularly steep climb i maxed out in garmin at 183bpm and averaged 152bpm over 50km or so.. The watch didn't record anything over 110bpm.
It's fun, it's quite nice, reasonably useful .. 700chf well spent, i'm not sure.