11 inch maxed out Air serves me well as a tertiary machine. I have an I5 2011 mbp that I use from time to time, (mostly as itunes library, but also to work on) in terms being portable and carting it to work and back the Air is great, also good for planes. If I am going somewhere for a long time, the then mbp is great. For major computing loads I use my desktop PC.
The 11 inch air serves many purposes, just probably none of yours. I could say the same of my brother who likes to game on his laptops, but again his uses are different than mine.
By your original argument the 13 inch macbook pro is only 35% heavier, but offers 4gb of ram natively, with capacity for far more, interchangable HD drives or SSD to your liking, Significantly faster CPU, backlit keyboard, increased battery life, add this to firewire, a superdrive (or bay or another HD so you can have a 600gb SSD + 1tB spinning disk) along with much lower cost, and you'd be a madman to consider the 13 inch air. Add this to if you were Adam Engst, you are only saving 7.8% of the weight of his bag if you were to use the 13 inch macbook air. lol
The 11 inch air serves many purposes, just probably none of yours. I could say the same of my brother who likes to game on his laptops, but again his uses are different than mine.
By your original argument the 13 inch macbook pro is only 35% heavier, but offers 4gb of ram natively, with capacity for far more, interchangable HD drives or SSD to your liking, Significantly faster CPU, backlit keyboard, increased battery life, add this to firewire, a superdrive (or bay or another HD so you can have a 600gb SSD + 1tB spinning disk) along with much lower cost, and you'd be a madman to consider the 13 inch air. Add this to if you were Adam Engst, you are only saving 7.8% of the weight of his bag if you were to use the 13 inch macbook air. lol