I am going to buy 11 inch MBA. To upgrade processor buyer needs to purchase 128GB model instead of 64GB. Because I do not need 128GB we will assume the cost of upgrading to 128GB is additional processor cost. Difference between 64GB with 1.7Ghz and 128GB with 2.0Ghz = 340 US dollars. Do you think this is worth doing for the price considering I do not need the extra 64GB so the 340 dollars extra is purely processor cost.