I know there are zillion threads about 13" vs 15" but I still do have the question in my mind for which I would appreciate some input... I bought my mid-2010 15" MBP (i7, 4Gb RAM) 3.5 years ago and I was really happy with it for all this time. It became a bit sluggish recently (HDD), and battery is pretty much dead. Also display have a few small bright spots. Now I am thinking of buying rMBP. The thing is I can't decide between 13" and 15". I LOVE portability of 13" as it's very good experience (compared to 15") to carry it around and I do it a LOT. I don't play any games on computers and I don't do heavy video editing stuff. I know if I buy 15" rMBP it will serve me very well in the next 3-4 years. But how about 13" - let's say I take the conf with 16Gb RAM. Is Quad core (or likely to be) a MUST have in years to come? Also I can survive next 6-7 months with my old mac. Do you think it's worth waiting for the next update? I know this is a bit "up to me" question, but I would like some input. Thanks!