I get between 8-9. I use safari, and stripped out some of the bells and whistles. Siri, KB back lighting, auto brightness, shut off blue tooth, and notifications, and only keep open what I am using. I also put Ghostery on Safari which made a big difference.
Overall its a pretty much a fact that the battery life could be better on these new released machines. But overall it works for me for my daily use. If I put this thing to work, I am sure the battery would deplete a lot quicker.