I played a bit with one of these in an Apple Store. I really got the feeling that it was unsuitable for GUI applications, unless you had razor sharp, eagle-eye eyesight. If you just ran text mode apps all day, it might've been totally brilliant.
13 year ago I had a professor who had one of these 11" Airs for this exact reason. He was always tunneled into some other system and the Air primarily served as his terminal. He loved it for that.
It was also pretty great for media consumption on the go in a world before iPads. I always felt like it compared with the netbooks, and preferred the full OS on a real machine than the watered down netbooks, but agree it was most impactful for my time in editors and terminals and not UI apps.
I had one for a while. Usually I would have IntelliJ, a terminal, and a browser all fullscreen and I'd 3-finger swipe between them. It worked reasonably well.