I am proposing to switch from a pc and want a 4GB 13" but will still want to use Windows with parallels. I will mainly do light stuff - Office (excel, word, outlook) and surfing. The store guy said definitely get 256 drive if installing Windows and to get the faster i7 processor not the i5. Will this make much difference? I am quite prepared to pay the premium for the i7 but don't want noisy fans or overheating (or reduced battery life) especially if it won't make much difference. I presume he is right about the 256 drive compared to 128. I'm new to this and have looked at the other threads but would appreciate your sage comments.