hello, im looking at ugrading from a 2013 13" macbook air and it is slow its only got 4gb of ram and a 128gb ssd. it is slow! i want to upgrade to eaither a 2012 15" unibody macbook pro with a 1gb gpu or a 2013 15" macbook pro. my question is my budget is $400 and i dont know what to get i want a 2012 unibody macbook pro but i know those have gpu issues right? otherwise its a 2013 15" macbook pro. what do you guys say?