I'm going to buy a new laptop in few hours having instant need of it, it has to be a long term purchase(4+ years), but I don't know if the 13 inch(I need a 13 inch one) i7 worths the difference of price with the i5 one. what I intend to do is: browsing, video streaming, netbeans, web programming(from web sites to web applications), xcode, aperture(not very frequently), and having an external monitor I intend to make an intense use of a virtual machine during the previous operations. The questions are: - the 13'' base (i5, 4gb ram) is sufficient for my purpose? - Will I have significant advantages with the i7 one? - Is a good idea to buy the 13 base one and install 8gb ram and a 256gd ssd instead of buy the 13'' i7 one? Thanks in advance.