Help!! I am looking to purchase my very first rMBP and I don't know which one to purchase: the 128gb or 256gb? I have a couple of songs in my itunes, but I don't think it'll take up too much space. I also don't have any movies/videos stored in my current desktop. Also, I don't keep a lot of photos on my current desktop. Although I will be keeping a lot of documents because of school- I am currently in high school and I wish to use the rMBP for my post-secondary education, which is not until 2018. (I want to take up marine biology or virology- if that means anything in regards to my purchase of a rMBP) As of the moment, I am leaning towards the 128gb, but I am very indecisive! What do you think?