I didn't find that to be the case. The ThinkPad X1 Carbon was the only Ultrabook that compared at all favorably to the Air in reviews, and it costs something like $1450 versus $1140 for the Air. Thought about it. Couldn't justify the higher price. (Edit: Price has apparently dropped, see below)
Another contender was Asus' Zenbook Prime, which got mostly good reviews and is cheaper than the Air. But it's only slightly cheaper ($1080) and the Ubuntu wiki mentioned a bunch of ugly issues I didn't want to deal with: https://help.ubuntu.com/community/AsusZenbookPrime
Xubuntu (Ubuntu with the Xfce desktop) is my favorite operating system. I'm not settling for less by using it. I set out to run Xubuntu on a great, lightweight laptop with an SSD, and the Air was the most compelling option. Simple as that.