I have the 2011 Air with the 1.7 GHz Core i5 processor and I'm thinking about getting the new 2013 Air with 1.3 GHz Core i5. I'm concerned about the processor speed as I use a lot of resource intensive programs. I'm assuming the new processors are somehow faster, but the 1.3 vs. 1.7 seems like a big difference so I want to make sure I wouldn't be taking a step-down as far as processing speed.