I have this year oryx pro from this year. The battery life is ok to poor and honestly is one of the weaker attributes of the machine. (You have to switch to intel graphics, with nvidia on be plugged in). right now I'm at 40% battery and it says I have 2:20 minutes left, but honestly I'm browsing the web.. under load I think I get 2-3 hours with a full charge.
Got a 17" Oryx pro last week. So using it with integrated Intel graphics, power saving on and screen brightness low, it's about 4.5 hours. I noticed if I adjust the screen brightness like even 10% it can add an extra 30 minutes. I'd assume it might be even longer for the smaller screen oryx versions. Now im wondering if there are a few other kernel governing tweaks that'd increase the time.
That being said I really like the machine.