I've tried Chrubuntu and it doesn't work as well as Crouton. The wifi, specifically, is flaky. Have you had better luck with the Chromebook 2 specifically?
It's been a while since I've used it and it turns out it's a first generation Samsung Chromebook (XE303). I don't remember having any WiFi-related issues.
The source code used to build the kernel for ChromeOS should be available so I'm surprised this sort of thing is a problem.