There's no official, user-friendly way to install ChromiumOS yourself. A company called Neverware provides ISOs for x86 PC's but like you say the drivers are spotty and these releases lag behind ChromeOS. I'm not even sure what tablet devices are out there that you'd _want_ to install ChromiumOS on yourself? Maybe a Surface? These don't even have mainline Linux support (https://github.com/linux-surface/linux-surface exists though).
ChromeOS on a device like the Duet is a nice experience however, and still let's you get a Debian shell like I described.
