Dilemma: Seen an Early 2011 13in i7 for £999 which is a £300 discount from original price. Amazon selling late 2011 13in i5 £899 which is a £100 discount. A £100 for an i7 is it worth it? Macworld speed tests seem to show the late i5 as faster in a lot of the test. Is this correct? Would appreciate any thoughts to help me choose. While i am not a heavy user i do like to future proof where i can.