Hi, I have recently built myself a pretty powerful desktop PC so now have little need for the power of my macbook pro. I have a buyer lined up for the macbook pro so my original thought was to buy a macbook Air with the money from the sale of the pro. Now that I have a powerful desktop I want my laptop to be very portable so I can just take it where ever I go without feeling like im lugging something about in my backpack. All I will be doing with the computer is web browsing, reading kindle books, some hobbyist level photo editing, occasionally playing Counter Strike or Diablo 3 (probably once a week at most), general word processing and listening to music. For this I am looking at the top spec 11" air, the native resolution being less than the 13" version should benefit me when playing those games, I don't NEED the extra screen real estate of the 13" for any of my uses. What I was wondering is the processor upgrade to the 2.0Ghz i7, how much of a performance increase is this over the i5 1.7Ghz? This upgrade is £100, I am buying through the education store so will get 3 years of applecare and that is how long I intend to keep this machine so would that processor upgrade be worthwhile? The spec I am looking at is : 2.0GHz Intel Dual-Core Core i7, Turbo Boost up to 3.2GHz 8GB 1600MHz DDR3L SDRAM 128GB Flash Storage £970 or £870 without the processor upgrade. I noticed I can now get a 13" retina for £1070 but as tempting as that is it would probably just be overkill for my needs as nothing I do actually needs the retina resolution. So I guess my real dilemma is i5 or i7?