[Crusse]

If you go for a Chromebook, check out this Xubuntu-based OS that's designed for ChromeOS devices: https://galliumos.org/

You can also permanently install a non-ChromeOS OS on (some?) Chromebooks, but you might have to fiddle with a BIOS flash and a write-protect screw first.

[partisan]

I use GalliumOS on a Dell ChromeBook 13 (i5/8GB). I don't have any issues except that the machine reboots itself during sleep sometimes. That's not a big deal for me, so I am very happy with the experience besides missing Ubuntu Unity after working on it for several years now.

EDIT: I used chrx to install it. I don't recall any issues during the process. I also upgraded the SSD to 256GB.