I am about to buy my first Macbook, and I don't know which one to buy. I can buy the 2.26 and upgrade RAM to 4Gb and upgrade to 320 Gig HDD, for the same price as a 2.53 Ghz with 4 Gb RAM and 250 HDD. Is the 2.53GHz processor worth getting over 2.26? Is there a noticiable difference in the speed for online browsing, games, typing essays etc?