As some of you may have seen I was pretty vocal with my disappontment in the rMBP battery life. I was getting 4 hours on a good day just vanilla out of the box. Few installed apps etc. The two things that have made a difference are: 1. Turning off Bluetooth. Par for the course probably, but BT in this machine seems to be hideously more of a power draw than on any other machine I've used. 2. Power cycles. Although Apple says the battery in this comes pre-calibrated, i've found after 10 power cycles i'm now getting much better battery life. I have just about managed 8 hours from a single charge today and am down to 4%, including web browsing, VPN/remote desktop over wifi, and around an hour Spotify (playing through the speakers, not headphones). Screen brightness 2 notches over half, keyboard illumination up two notches. Actually now very impressed with the battery life. So anyone else disappointed with it out of the box, give it a chance to settle in. Not sure what's different about the battery in this machine, but it's had the worst out of the box performance of any macbook or even windows laptop i've owned before, but now it has the best battery life of all of them. Can't wait for Mountain Lion now to see what improvements that brings.