I have two Chromebooks. One with 3G, that runs the stable ChromeOS, and the other wifi only, runs ChromiumOS, latest ToT, mostly because I'm working on getting ChromiumOS to run on our hardware, so it's a bit easy to compare and contrast when things are working and when they aren't. It's dead simple to boot off an sdcard or USB stick. The Chrome/Chromium did a REALLY good job at making the information available.
I'll probably buy the Pixel as well. The more I use ChromeOS, the more I realize how much time I waste on other crap that doesn't really help me get done what I want to do. And using ChromiumOS, there is the "dev_install" command which will set up a Gentoo chroot in /usr/local, that points to the machine that you built it on, and if you're running the devserver, you can run emerge pkgname, it will shoot it off to the server to build it, and once it's done compiling, installs in the chroot. There is also gmerge which will install ChromiumOS packages for you (e.g. A new version of the browser or maybe a newer kernel, without rebuilding everything) OR you can build a new image, hit up the Help page in settings and it will generate a diff on the server and update the entire install to the latest image. It's really an interesting setup, and I really like it.
Everything goes through gerrit, so you can even help out with version bumps and or patches fairly easily. The documentation is really good, and if you happen to hang out on IRC, the ChromiumOS developers are extremely helpful when something isn't clear, and even update the documentation for clarity.
I'll probably buy the Pixel as well. The more I use ChromeOS, the more I realize how much time I waste on other crap that doesn't really help me get done what I want to do. And using ChromiumOS, there is the "dev_install" command which will set up a Gentoo chroot in /usr/local, that points to the machine that you built it on, and if you're running the devserver, you can run emerge pkgname, it will shoot it off to the server to build it, and once it's done compiling, installs in the chroot. There is also gmerge which will install ChromiumOS packages for you (e.g. A new version of the browser or maybe a newer kernel, without rebuilding everything) OR you can build a new image, hit up the Help page in settings and it will generate a diff on the server and update the entire install to the latest image. It's really an interesting setup, and I really like it.
Everything goes through gerrit, so you can even help out with version bumps and or patches fairly easily. The documentation is really good, and if you happen to hang out on IRC, the ChromiumOS developers are extremely helpful when something isn't clear, and even update the documentation for clarity.