Time moves on. Chromebooks are moving as well. Their usability is getting better and better.
For last few weeks I have been using Office 365 (in particular Word) as I am in process of finishing new book.
What is good? Integration. Using last Office Online extension user is allowed to access One Drive repository without any limits, store documents, manipulate with them and every possible thing you usually do inside One Drive. Of course, there are still limitations in Word Online. But please, have in mind, you are not limited in a way you may think of limitation, it is just an little obstacle to be honest, nothing that will making troubles or something. Do not hesitate do use it in everyday work. It is that good.
Excel is not different. Just use it. I am not heavy Excel user privately so I cannot comment too much but have in mind that all formulas, pivoting, reports, functions, filters and everything else is working without any problems.
PowerPoint is a little different beast. I avoid it as much as I can. See for yourself. 🙂
What is bad? You have to spend a little time getting used to work with it. But do not worry. As normal people are able to switch from iOS to Android or vice versa, they also can switch (or just sometime use) between offices.
Just do not be afraid. Jump into it. Please, have in mind, I primary mentioned Word Online and briefly Excel. There are whole bunch of other things there. Try it.