I keep telling myself, when I have the funds for a rMBP, I will undoubtedly outfit the machine with 16GB of RAM. While I don't need it now, my needs may change down the line. Well, I was thinking. Given how challenging these machines are to repair (I don't even know how Apple does it), and given that AppleCare is a must, there is an inherent risk to keeping the machine beyond 3 years. Why future proof these devices for 5 years when 40% of the time you have it the computer is at risk of a fatal, non-repairable problem?