Just picked up the 27in display today for the office. I was surprised how well the 11in MBA base model handled driving such a pixel-dense display. Although, I did get feel some noticeable lag when I tried scrolling quickly while image-heavy websites were loading.
http://farm5.static.flickr.com/4027/5130894180_65d95bc849_z.jpg
Great setup, pretty similiar to what I'm thinking of getting, just with the older 24in ACD.
What spec air is that and what websites were laggy?