I am coming on 8 days of owning my 13 inch rMBP and I love it. But I just can't help to think about how much more computer you get with the base 15 inch.. I bought the $1999 13 inch rMBP (256 gig ssd upgrade). Any thoughts? I love the 13 inch size, but don't really require a small laptop. But I am worried that I will move to the 15 inch and not like it or have problems that the 13 inch does not have. Can I even exchange for a 15 inch and pay the difference?