So I'm in a pickle of what I should choose... My friend is selling me his Macbook Air rev b 1.86 ghz, 120 hdd with superdrive for $1250 with 3 yr applecare. Other friend of mine has a 2.0 ghz macbook unibody sealed for $850 with no applecare. Which should go with? Style OR substance? I really care about portability & which has a better screen.