I've recently purchased a rMBP 13", 16gb ram, 256 ssd, 2.7ghz, and I love this thing. But, the lag I am experiencing navigating the UI, scrolling pdfs in Safari, opening and closing windows, well it is a little unexpected given everything I always hear about OS X and MacBooks and the 1500 price tag. I'm considering going to the MBA or a windows computer just so I don't have to deal with this lag. I see comments all over about El Capitan fixing these issues but by the time it comes out, I will be past the return period. So, can the people that have been using the public release comment a bit more on the lag decrease? I know this question has been exhausted but it's just hard for me to justify having this great laptop that doesn't seem to function properly.