Hey guys, i'm planning to buy used MBA, but I'm not sure which one. I'll be doing light programming, mainly Java. Main things for me are screen, smoothness, battery life and i want a snappy machine overall. I have 3 deals base MBA 2010 for 600-650$, base MBA 2011 for 800$ and base MBA 2012 for 900$. What is the best deal, is it worth paying extra money, and what is the difference between them except processor and gpu? Thanks.