I'm curious to know what your battery life is? How is your performance on Mavericks, any beachballs? I do experience this every so often and worried when I start using photo editing software I'll see more. At the same time I'd like to future proof a bit, without taking a huge hit on battery life. I'm on the fence and thinking of returning my i5/4gb/256 and order this as I'm still withing my return period? Would you definitely recommend this? How long would apple take to receive it?