I'm going to be buying a new 13"MBP to replace a late 2013 15"MBP in the next week or so. I'm looking for some advice on processor choice. Can't really justify the price of another 15" and not sure I require the dedicated GPU. In real world use is there much difference? The most tasking thing I'll be doing is some photo and home video editing. I'll also be using Prism for medical data analysis but I don't think this is particularly processor intensive. I guess my main question is around longevity, I usually replace my laptop every 4-5 years. Thanks in advance.