I currently own an early 2011 13" MBP with 8GB RAM and a 256GB SSD + 320GB HDD setup. It's running fine of course but there are certain things that I would like, such as a retina display and maybe a discrete graphics card to venture into some gaming through Steam. The size and weight is pretty good too; I have no problems walking to uni whenever I do need my MacBook however this is rare as my maths degree doesn't exactly require a lot of essay writing (yet?) My current needs are mostly media consumption, browsing, document writing, some photo editing via Lightroom and that's pretty much it. Now my question is, is a 15" rMBP overkill for my needs? Bearing in mind that I probably won't move around with it that much so portability isn't much of an issue. However, would a 13" rMBP + external display be better? Would like some opinions, thank you.