A friend of mine is willing to sell me her Macbook Air from 2011 for about $500. I currently use a MacMini that is from early 2010 and I am looking to upgrade. Ideally, I want a MacBook Pro but that won't be in my budget for a good while. I don't know much about the MacBook Air. Would this be an upgrade? Is it a decent computer? Any input/info about the MacBook Air would be appreciated because I just don't know much about it.