I just got a replacement 2015 MBA 13 (1.6/4/128) after my old one required three logic board replacements in 3 months (!!). Since it is brand new and there are better values out there, I decided to sell it for what I can buy a refurb rMBP 2.4/4/128 for. But now that I think of it, I also have the option to take my brother's old 2010 MBP 13 (2.4?/4/256 HDD, just had the battery replaced) and upgrade it. Would this be worth upgrading to, say, 8GB RAM and an SSD? I'm a fairly low-density user (think non-art student stuff) and the base MBA has suited me so far. Of course, I would lose out on the retina display, 9+ hour battery life, and USB 3.0, but how would the processor hold up in a few years? Is it worth the ~$450 upgrade or should I go for the rMBP?