So I bought a 2013 Macbook Air 11" about 3 weeks ago, just a week short of the return policy. (****!) Now, I'm starting to get into programming and I'm realizing how much I'd need the 13". I can sell my Macbook Air on Amazon for $900 and buy a 13" refurbished from Apple for $849. I'm 16 and I saved all summer for this so just selling the 11" and getting a new 13" is not an option. Especially since I got the computer for $900 Brandnew at Microcenter. How much performance will I lose? - I surf the web - Program (Sublime Text, Eclipse) I admit, I'm stressing over that battery life.