I'm having trouble deciding weather I should get the 256GB Flash Storage MBPr or the 512GB Flash Storage MBPr. I have an iMac (Mid 2011) which is 1TB but I have only used about 100GB and a MacBook Air (Mid 2012) which is 128GB but I have only used 30GB. I'm wondering if the difference of the 2.6GHz to the 2.8GHz is notable. Thanks! Went with the 128GB MBPr (Mid 2014.) Thanks everybody!