With the new 2015 13" rMBP, will you see a real performance difference with the base 8gb vs upgrading to the 16gb? Particularly in edit GoPro video- I use a late 2011 15" MBP 2.2 with only 4gb of ram and it doesn't do well with video related stuff. GoPro studio works ok I guess. This machine will be running Traktor scratch pro 2, creative suite, and most likely final cut pro every so often for fun to cut GoPro videos. So will 8gb be enough or should I spring for the 16gb? Also, how much space do the OEM programs take up from the 128gb harddrive?