I find Google Docs frustrating to use. I dislike that we don't have a packaged app for docs. Why is it that when I click on word processor or spreadsheet or whatever, it automatically opens a new file and creates that file on Google Drive? I periodically have to clean out my drive because of this. Not being able to click the icons on the launcher without opening a new instance is annoying as well (a frustrating change that rolled out a few months ago in an OS update when they were making packaged apps more robust)
Beyond these petty annoyances, the application works well enough beyond that. Chrome Remote Desktop is outstanding if you've got a Windows or Mac PC to call home to. Google Keep is definitely better than scratchpad and works great as a basic note-taking app. I wish that chromebooks had been around when I was in college. Mine is my primary computer (I have a gaming PC but it needs fixing and I've been to cheap/lazy to get to it) and since I don't need it professionally, it gets me by for basic entertainment purposes and posting long-winded forum rants.
Compatibility between different word processors seems to ALWAYS be an issue. I write it in Google Docs, she opens it in Office 2010. Shenanigans ensue. I'm kind of a power user so I have a Linux environment set up on an SD card for my chromebook. If I ever have any serious work to do (besides typing up campaign notes for Dungeons & Dragons), I turn to LibreOffice. Google Docs is a real weak point of the whole thing IMO