I usually leave work (12 hour shift) with around 13.5 hours of standby and 3-5 hours of use. All I did was turn off my safari iCloud sync after reading some posts saying it would increase battery life and in 24 hours, what a difference it seems to make so far. I was able to squeeze an extra 3 hours of standby per same amount of use and at the same battery level. These were taken on two different days, after work and when I finally got home. The safari data was the only thing different between the two.