Wondering if the 2013 is worth the money, or do I get a honker 2012 Refurb, I was looking at the 13" with the fastest CPU and 8GB and 256 or 512 but just not sure the 2013 is worth that much more. I guess the battery life is good, just curious if anyone had a 2012 and now has a 2013 and is there a huge difference?