I am currently a senior in high school and am looking into getting a macbook pro for college. I have recently been using a slightly upgraded 2012 non retina mbp (not mine, family laptop) and want to buy a newer one for college. I carry this one with me every day in my backpack, and weight and portability are not a huge issue. I'm majoring in Biochem, and will likely be using excel a lot. We have an iMac that I use for all my big projects just because of the extra space, and really like being able to use all that space. This caused me to question whether I should be looking into a 15 inch pro. I'm planning on buying a 2015 because the new mbp's do not appeal to me at all, and am looking at the refurbished models from apple. Are these models generally reliable or will they be more run down and die faster? Basically I need advice on what to prioritize when looking through refurbished laptops, advice on 15 vs 13 inch for college, and if anyone has experience with buying apple refurbished products I would greatly appreciate some insight into the quality. Thanks! EDIT: I also might want to dual boot because I know many programs in medicine only run on windows. Never done this before and not sure what the performance requirements for this are.