i am looking to replace my old MacBook, since it refuses to run more than one app at a time. Could someone please explain to me, in non-highly-technical language, the benefits of these respective models, mainly in terms of processing speed? I'm a college student, I do basic web browsing and word processing, with some use of numbers and keynote, and I don't really do video editing. Is it worth it to upgrade the processor on the MBA, if I have 8 GB either way? And, given my limited college-student budget, and that I don't really care about screen quality, would the rMBP be worth it for my needs? Also, how does the i5 and i7 and Turboboost figure into all this? Again, I'm not exactly computer-savvy. Thanks so much!