6 hours battery life is putting it a little low. Got mine since Friday 19th and have been using it since.
The battery holds for about 14 hours with on and off (regular) usage.
But as with all new devices, you'll probably drain that thing dry in about 5-6 hours, since you will be fumbling it all the time.
But as time goes and you'll use it normally, you should see a days worth of usage from the thing.
What concerns me, personally is the stability of the Software.
I don't know, how much is the apps fault (fixable), or that of the device (I've read no mention of it being update-able).
I already wrote SE for a statement on the matter.
As it is now, the device regularly quits working.
It wont go further then showing you the watch (time and date).
Nothing else.
After turning it off and on again, it automatically connects again and works though (taking about 10 seconds and two button presses).
With that behavior it's quite unreliable for notifications (it's main purpose).
I hope, SE can somehow fix that.