I am consistently getting around 5 hours. I am not happy about this as I bought this device specifically to get to a single device and need long battery life. I didn't expect a full 9 but do expect 7-8 when doing typical things like email. Word, PowerPoint and web surfacing.
I have been keeping up to date on the firmware and drivers. Screen brightness is at 26% on battery and 60% on power. I have tried mot all of the suggested tweaks.
I have the i5 with 256 hard drive.