Hi all, I'm currently still using a 2009 MBP on Snow Leopard, it's running more or less fine but I'm thinking it's about time I upgrade. Looking to get a 13" rMBP 3.1, 16GB. I was wondering how much of a boost it would be performance wise. Obviously it's 6 years newer but from what I hear Yosemite is a bit of a power-hog and the 4x retina graphics might eat up a lot of juice too. Will I see a noticeable difference from my Snow Leopard machine or should I think about maybe waiting till the next MBPs are out?