So I just received my MBP yesterday and I'm loving it. I got the top end 15". It runs like lightning but I was wondering. Because I've had problems with my old Windows PC (yes I'm a new convert) and that over time just slowed down to where I could do next to nothing on it. So my question is will my new computer be just as fast in 6 months as it is now? Or how long does it usually take for these things to start slowing down? Thanks!