I have an older Chromebook (Samsung Series 5, Alex codename) and I now have it running Ubuntu. The only thing that I dislike is that the ChrUbuntu script I used is using the ChromeOS kernel and runnig Ubuntu on top of it, so I am missing support for a whole range of devices because they are not included in the default kernel for ChromeOS... that is going to take me digging some to figure it out and compile my own kernel.