I supported a NextCloud + OnlyOffice server for 4 years for a 100-person company, and have since moved to Collabora Code (which has been running for ~2 years now). IME Code has better performance, is easier to upgrade, provides better compatibility with MS Office (since it's basically LibreOffice with a web UI), and is easier to integrate with (I wrote some integrations for a couple of internal systems and it's been a breeze).
Good to know. I’ve been sticking with OnlyOffice only because it’s supported out of the box on Hetzner [0] (as in, I don’t need to setup and maintain any “document server”). Surprisingly, this is what they say about Collabora:
> Due to performance reasons, we cannot support the built-in version of Collabora. So if you still want to use Collabora, you will need to provide your own server. You could use, for example, one of our unmanaged dedicated root servers or a Hetzner Cloud server. You can activate Collabora via the App Store, but you will need to use the other server for data processing. You as the customer are responsible for configuring this server yourself in the app's settings.
It's fully FOSS. https://www.collaboraonline.com/code