Thanks for your comments Chas. You have reinforced the point I was trying to make, i.e. that the claimed battery performance is not reached under normal conditions of use. The battery lasts a very long time when not in use - far longer than the battery in my 2008 MBP. So that's in part why I questioned the surprisingly poor performance. My MacBook Pro was set just above mid point brightness for outdoor use, battery was fully charged, there was no video content, sound connection or Bluetooth connection. I question whether WIFI searching would reduce battery life from 10 hours (you are correct about that) to 4, and if it did, that suggests that Apple is even less transparent in its claims for battery life, or it should specify more clearly conditions under which maximum battery performance might be expected. Apple also claims "up to 10 hours" battery life "so you're free to keep watching, gaming and editing from wherever you are." It's clear that those demanding uses would not allow such battery performance. My comment is just a reminder that manufacturer claims will not match normal, average, call it what you will, user results, unless you leave it on the desk, closed. Still, I am very happy with my MacBook Pro, but please, find a way to suggest realistic expectations. How about "battery life from 4 to 10 hours"?