I need some buying advice. I am torn between these two products. I would like to have the better display from the retina and it does offer better performance, but I am not sure I need it with what I do; which is mostly: Browsing, photo editing pictures from my DSLR, word documents; will use it for grad school in next year, movies. The air appears to me because it is cheaper and the pro because of the screen. The biggest hangup I have is over the space. It costs a lot to upgrade from 256 to 500. Is buying a network storage device the better way to go as far as this is concerned? if that is the case the mid level 13 pro would be ideal for me Opinions?