There's always the Dell XPS 13.
I routinely boot the same linux-USB desktop distro on both.
The XPS is probably a bit faster (i7), and screen DPI is better. But, MBA provides and overall better experience.
The most glaring things that stick out in MBA favor is: (a) keyboard, (b) touchpad.
The XPS touchpad is really sub-par given the focus of the machine as a development platform. Often while typing, the slightest brush against it will cause the cursor to jump. This is not an issue on the MBA.
My WiFi does seem rather poor in terms of signal strength/stability compared to other devices I own, however.