Just received the OTA. About 10PM GMT in UK.
Android Wear: 1.4.0.2576000
Google Play services: 8.6.98
Android OS: 6.0.1
Build number: MEC23G
Initial impression:
1. The new gestures are awesome. It will be super handy for stopping/playing music. At least with Google Play Music card when you pull the hand up or down, it does move to the next page rather than activating the button. Same with SoundCloud.
2. The default launcher is faster at least for now. Maybe I will start using it instead of WearMini Launcher.
3. Scrolling with gesture in cards is cool. I can see myself doing it often.
4. I haven't messed with the permissions. I do notice some apps (Guns'n'Glory, Ingress, PaperCraft, Google Play Music to name a few) are not present in the permissions tab. I haven't uploaded any music from GPM on the watch and I don't think the others have any special permissions.
It is too soon to tell if the stability or battery life has any change.
I do see "Vibrate on connectivity change" inside Developer options. And one new entry "Audio Injector" inside Wear Developer Options. And yes, the restart option has been removed. Bummer.