MBA has an excellent button-less muti-touch trackpad that's highly accurate and comfortable to use.

The 11" model lasts up to 9 hours and the 13" model up to 12 hours. Great for programming on the go as you don't have to worry about the battery dying.

The MBA has a well-spaced, back-lit keyboard with convex keys and placed in way that the resting arms on the sides of the trackpad is comfortable.

Macbook Air has a high quality all-aluminum body that looks great and is sturdy enough that worries of accidentally damaging are mostly alleviated. It has a robust lid, well-spaced back-lit keyboard and an excellent button-less trackpad.