I don't think any watch does this currently due to battery life.
My LG G Watch R is on all the time and still lasts almost two days.
I wanted this because bo matter how good your 'tilt to wake' detection is, with normal watches I often just glance at them without moving my arm at all, or with a tiny twist of the wrist.
I'd have thought with an OLED screen apple could have managed at least a dim screen or just the watch hands on all the time - should barely use any battery.
I like the sound of how they deal with notifications. One issue I have with android wear is that notifications don't go away on their own, and they require a tap to read or dismiss. Apple watch sounds much better:
- receive notification, raise arm to read.
- put hand back down quickly, notification is dismissed on watch but remains on phone for later.
- keep hand up, switches to read mode and shows you more information. Notification is dismissed on phone.
I'd like android wear to copy that please - need more hands-free interaction.