One interesting example is that if I have a file I want to open, it doesn't matter if it's Chrome, Android, or Linux that has the executable to open it. I just click the file and it opens in the right app. I can also open it in any other apps via a dialogue that lists things I can open it with. The list shows all relevant Android and Linux apps.
The app launcher is similar -- all apps, regardless of how they are run, show up together.
I'm still not sure I could give up my Mac for my day job, but for personal use, I love it.
You don't need to turn developer mode on for this feature. That means you get verified boot , updates (including your Linux distro) as well as the security guarantees of Chrome OS. Crouton requires you to give up all of that. You can't get sync without signing in. Cloud sync is the foundation of the OS. It's what makes it stateless. If you don't like that it's not for you but stop spreading half truths about the product in bad faith.
Google says that ChromeOS has "simple setup" - but not the Linux parts. They say you can "search anything on your Chromebook" - but not Linux. They talk about "Chrome sync" - doesn't apply to Linux. Etc.
I think that ChromeOS has value as a web-browser host, and also as a development machine for vim-jockeys. What's missing is the middle part: a real desktop OS.
You can search linux files and apps as usual.
As for sync, feel free to look at open bugs and features and see the work being done.
What makes it work is that everything you could possibly want to run either runs in the browser or in a remote machine.