Actually I am everything but happy with OnlyOffice. I got it running after 2 weeks finally and now that I can finally see what it is actually capable of, I am very disappointed.
There is no obvious way to change the GUI language to the preferred one and while some of my users are not very comfortable with using an english Office GUI I can’t use it like that. When you have a look at the forum of Onlyoffice (http://dev.onlyoffice.org) you may be shocked as much as I am. This looks like pretty dead community there and the forum is HTTP only (no even for login form HTTPS) and when you post a question you have to wait days before the moderation had reviewed your question and passes it on to the public. And then the moderator is the only one answering (my impression).
The feature list of Onlyoffice is pretty small. There is no “conditional formatting” (if that’s the correct name of that function) and no pivot tables.
What I also expected was the possibility to share a Excel file to the public and edit the file collaboratively with users that don’t have an account on my server, but that’s not possible. Other users can only download the file then.
I’m already thinking about uninstalling Onlyoffice again and giving Collabora online a shot.
Oh, some hints: when you want to install Onlyoffice on the same server as Nextcloud, make sure redis is not running in socket mode for Nextcloud. You need to have redis running in TCP mode and listening on port 6379.
Furthermore don’t disable IPv6 via sysctl.conf - I did and then nodejs will not open port 8000.