I have a mid-2009 MBP. 17" Aperture, iLife, iWorks, MS Office, etc etc. I like the thinness of the Air, and the portability. I'm thinking of trading for a 13" air. My MBP is the 2.8ghz Intel C2D, 4Gb/500GB I dont really burn cd's or dvd's, if I do, I'm sure I can use an external drive. Basically my question is what would the pros/cons be of a trade like that? Any real performace difference? Any opinions/experience sharing would be great!