Just a quick note... The new displays are significantly brighter than the old ones. I have a retina 15" and an Air side by side with my TMBP. It may be that some users are keeping their brightness cranked up. I'm using Lightroom and PS and use that brightness for photo work, but the rest of the time I dial back to normal brightness. I'm getting 8 to 10 hours. Naturally, the apps you use will factor in hugely, but after 8 cycles of charging, my 13" is living up to the battery claims. Since some youtube tests also show good battery life, we're left with the following: Some units have bad batteries. Some users have brightness too high. Some users have software that is effecting battery life. R.