I have a MBP that is showing age. I'm thinking of a buying a new (well, refurbished) one. I was looking online to compare speeds but I couldn't find the answer. So, simply put, I'm looking at a 2012 or 2013 refurbished MBP that has a 2.3GHz Quad-core Intel i7. My current 2009 machine has a 3.06 GHZ Intel Core 2 Duo. Which of these is faster?