the MBA is delightfully light — I think it's about the same as a 24-70 lens. the screen is bright and given max RAM and an SSD it's fast as hell. throw aperture on it and get an external drive (western digital is what I use) that connects via firewire or thunderbolt and you are set. I use aperture.

I carried around my trusty 17" mbp on my last trip and while the screen is fantastic I was seriously thinking about a 13" mba instead.