The 13" Retina MacBook Pro [1] matches the wifi Pixel in almost every characteristic except the touch screen, and is just $200 more expensive for the model with 128GB storage. However, there's no LTE option.
Is the pixel's screen really an "overall smaller package"? With an aspect ratio closer to square, it gets more surface area per diagonal inch, I would imagine it is actually larger than the 13in macbooks' screens even though it is only 12.8in or whatever.
Unless you can't stand OS X. Also the "Better Trackpad" is arguable. And I'll take the Pixel's screen.
MagSafe is a big draw though, arguably as important as almost anything else. Comparing the screen on my MBA to the screen in the new Dell Developer laptop with IPS is a bummer though.
In all honesty, I've never even seen a USB3.0 device in the wild either. Not an argument against the option, of course.
Nope, Ubuntu 13.04 works perfectly out of the box on my Air. With older versions you have to install more stuff to make sure the fans kick in, etc.
edit: Actually, hotplug Thunderbolt is touchy in Linux 3.8 because Apple's thunderbolt implementation is back-ass-ward stupid, but that's not really a biggie, I don't use Thunderbolt for anything really (the display out is fine)
Another difference between MacBooks and Chromebooks is the guaranteed availability of Linux drivers. If you buy a MacBook to run Linux, you have to do your research first, just like a Windows laptop.
Are there any mac components that don't have full linux support? I would expect that Mac's are so popular with geeks, they would have full driver support, but I never checked.
[1] http://www.apple.com/macbook-pro/specs-retina/