planning on getting a new 15" macbook pro and running logic 8 (first express then full version). price is somewhat an issue but i dont want to be shortsighted either. is the base 2.53GHz going to be good? any need to upgrade the HD to 7200 rpm, i;'m planning on expanding to 500GB either way? at this point, planning on small projects with a mix of audio and MIDI, nothing too complex. thanks