I'm wondering how long a rMBP should last. The cMBP lasts around 6 years. But since you can't upgrade ram in it after a time, will that affect the life if you already have 16 in it at the beginning and leave it in? Would it be better if you (could) start with 8 and when it slows down you upgrade to 16GB? I hope that if i treat my rMBP (when i will have one) nice and take good care, that it will also last 6 years about. I would use it for everyday normal usage and bit of gaming.